mtd: rawnand: sunxi: Add A23/A33 DMA support
[linux/fpc-iii.git] / kernel / trace / ftrace.c
blobfa79323331b22f327872ae41e185a17562f6d78a
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Infrastructure for profiling code inserted by 'gcc -pg'.
5 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
6 * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com>
8 * Originally ported from the -rt patch by:
9 * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com>
11 * Based on code in the latency_tracer, that is:
13 * Copyright (C) 2004-2006 Ingo Molnar
14 * Copyright (C) 2004 Nadia Yvette Chambers
17 #include <linux/stop_machine.h>
18 #include <linux/clocksource.h>
19 #include <linux/sched/task.h>
20 #include <linux/kallsyms.h>
21 #include <linux/seq_file.h>
22 #include <linux/tracefs.h>
23 #include <linux/hardirq.h>
24 #include <linux/kthread.h>
25 #include <linux/uaccess.h>
26 #include <linux/bsearch.h>
27 #include <linux/module.h>
28 #include <linux/ftrace.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/ctype.h>
32 #include <linux/sort.h>
33 #include <linux/list.h>
34 #include <linux/hash.h>
35 #include <linux/rcupdate.h>
37 #include <trace/events/sched.h>
39 #include <asm/sections.h>
40 #include <asm/setup.h>
42 #include "ftrace_internal.h"
43 #include "trace_output.h"
44 #include "trace_stat.h"
46 #define FTRACE_WARN_ON(cond) \
47 ({ \
48 int ___r = cond; \
49 if (WARN_ON(___r)) \
50 ftrace_kill(); \
51 ___r; \
54 #define FTRACE_WARN_ON_ONCE(cond) \
55 ({ \
56 int ___r = cond; \
57 if (WARN_ON_ONCE(___r)) \
58 ftrace_kill(); \
59 ___r; \
62 /* hash bits for specific function selection */
63 #define FTRACE_HASH_BITS 7
64 #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
65 #define FTRACE_HASH_DEFAULT_BITS 10
66 #define FTRACE_HASH_MAX_BITS 12
68 #ifdef CONFIG_DYNAMIC_FTRACE
69 #define INIT_OPS_HASH(opsname) \
70 .func_hash = &opsname.local_hash, \
71 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
72 #define ASSIGN_OPS_HASH(opsname, val) \
73 .func_hash = val, \
74 .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock),
75 #else
76 #define INIT_OPS_HASH(opsname)
77 #define ASSIGN_OPS_HASH(opsname, val)
78 #endif
80 enum {
81 FTRACE_MODIFY_ENABLE_FL = (1 << 0),
82 FTRACE_MODIFY_MAY_SLEEP_FL = (1 << 1),
85 struct ftrace_ops ftrace_list_end __read_mostly = {
86 .func = ftrace_stub,
87 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_STUB,
88 INIT_OPS_HASH(ftrace_list_end)
91 /* ftrace_enabled is a method to turn ftrace on or off */
92 int ftrace_enabled __read_mostly;
93 static int last_ftrace_enabled;
95 /* Current function tracing op */
96 struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
97 /* What to set function_trace_op to */
98 static struct ftrace_ops *set_function_trace_op;
100 static bool ftrace_pids_enabled(struct ftrace_ops *ops)
102 struct trace_array *tr;
104 if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
105 return false;
107 tr = ops->private;
109 return tr->function_pids != NULL;
112 static void ftrace_update_trampoline(struct ftrace_ops *ops);
115 * ftrace_disabled is set when an anomaly is discovered.
116 * ftrace_disabled is much stronger than ftrace_enabled.
118 static int ftrace_disabled __read_mostly;
120 DEFINE_MUTEX(ftrace_lock);
122 struct ftrace_ops __rcu *ftrace_ops_list __read_mostly = &ftrace_list_end;
123 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
124 struct ftrace_ops global_ops;
126 #if ARCH_SUPPORTS_FTRACE_OPS
127 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
128 struct ftrace_ops *op, struct pt_regs *regs);
129 #else
130 /* See comment below, where ftrace_ops_list_func is defined */
131 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);
132 #define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)
133 #endif
135 static inline void ftrace_ops_init(struct ftrace_ops *ops)
137 #ifdef CONFIG_DYNAMIC_FTRACE
138 if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) {
139 mutex_init(&ops->local_hash.regex_lock);
140 ops->func_hash = &ops->local_hash;
141 ops->flags |= FTRACE_OPS_FL_INITIALIZED;
143 #endif
146 static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
147 struct ftrace_ops *op, struct pt_regs *regs)
149 struct trace_array *tr = op->private;
151 if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
152 return;
154 op->saved_func(ip, parent_ip, op, regs);
157 static void ftrace_sync(struct work_struct *work)
160 * This function is just a stub to implement a hard force
161 * of synchronize_rcu(). This requires synchronizing
162 * tasks even in userspace and idle.
164 * Yes, function tracing is rude.
168 static void ftrace_sync_ipi(void *data)
170 /* Probably not needed, but do it anyway */
171 smp_rmb();
174 static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops)
177 * If this is a dynamic, RCU, or per CPU ops, or we force list func,
178 * then it needs to call the list anyway.
180 if (ops->flags & (FTRACE_OPS_FL_DYNAMIC | FTRACE_OPS_FL_RCU) ||
181 FTRACE_FORCE_LIST_FUNC)
182 return ftrace_ops_list_func;
184 return ftrace_ops_get_func(ops);
187 static void update_ftrace_function(void)
189 ftrace_func_t func;
192 * Prepare the ftrace_ops that the arch callback will use.
193 * If there's only one ftrace_ops registered, the ftrace_ops_list
194 * will point to the ops we want.
196 set_function_trace_op = rcu_dereference_protected(ftrace_ops_list,
197 lockdep_is_held(&ftrace_lock));
199 /* If there's no ftrace_ops registered, just call the stub function */
200 if (set_function_trace_op == &ftrace_list_end) {
201 func = ftrace_stub;
204 * If we are at the end of the list and this ops is
205 * recursion safe and not dynamic and the arch supports passing ops,
206 * then have the mcount trampoline call the function directly.
208 } else if (rcu_dereference_protected(ftrace_ops_list->next,
209 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
210 func = ftrace_ops_get_list_func(ftrace_ops_list);
212 } else {
213 /* Just use the default ftrace_ops */
214 set_function_trace_op = &ftrace_list_end;
215 func = ftrace_ops_list_func;
218 update_function_graph_func();
220 /* If there's no change, then do nothing more here */
221 if (ftrace_trace_function == func)
222 return;
225 * If we are using the list function, it doesn't care
226 * about the function_trace_ops.
228 if (func == ftrace_ops_list_func) {
229 ftrace_trace_function = func;
231 * Don't even bother setting function_trace_ops,
232 * it would be racy to do so anyway.
234 return;
237 #ifndef CONFIG_DYNAMIC_FTRACE
239 * For static tracing, we need to be a bit more careful.
240 * The function change takes affect immediately. Thus,
241 * we need to coorditate the setting of the function_trace_ops
242 * with the setting of the ftrace_trace_function.
244 * Set the function to the list ops, which will call the
245 * function we want, albeit indirectly, but it handles the
246 * ftrace_ops and doesn't depend on function_trace_op.
248 ftrace_trace_function = ftrace_ops_list_func;
250 * Make sure all CPUs see this. Yes this is slow, but static
251 * tracing is slow and nasty to have enabled.
253 schedule_on_each_cpu(ftrace_sync);
254 /* Now all cpus are using the list ops. */
255 function_trace_op = set_function_trace_op;
256 /* Make sure the function_trace_op is visible on all CPUs */
257 smp_wmb();
258 /* Nasty way to force a rmb on all cpus */
259 smp_call_function(ftrace_sync_ipi, NULL, 1);
260 /* OK, we are all set to update the ftrace_trace_function now! */
261 #endif /* !CONFIG_DYNAMIC_FTRACE */
263 ftrace_trace_function = func;
266 static void add_ftrace_ops(struct ftrace_ops __rcu **list,
267 struct ftrace_ops *ops)
269 rcu_assign_pointer(ops->next, *list);
272 * We are entering ops into the list but another
273 * CPU might be walking that list. We need to make sure
274 * the ops->next pointer is valid before another CPU sees
275 * the ops pointer included into the list.
277 rcu_assign_pointer(*list, ops);
280 static int remove_ftrace_ops(struct ftrace_ops __rcu **list,
281 struct ftrace_ops *ops)
283 struct ftrace_ops **p;
286 * If we are removing the last function, then simply point
287 * to the ftrace_stub.
289 if (rcu_dereference_protected(*list,
290 lockdep_is_held(&ftrace_lock)) == ops &&
291 rcu_dereference_protected(ops->next,
292 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
293 *list = &ftrace_list_end;
294 return 0;
297 for (p = list; *p != &ftrace_list_end; p = &(*p)->next)
298 if (*p == ops)
299 break;
301 if (*p != ops)
302 return -1;
304 *p = (*p)->next;
305 return 0;
308 static void ftrace_update_trampoline(struct ftrace_ops *ops);
310 int __register_ftrace_function(struct ftrace_ops *ops)
312 if (ops->flags & FTRACE_OPS_FL_DELETED)
313 return -EINVAL;
315 if (WARN_ON(ops->flags & FTRACE_OPS_FL_ENABLED))
316 return -EBUSY;
318 #ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
320 * If the ftrace_ops specifies SAVE_REGS, then it only can be used
321 * if the arch supports it, or SAVE_REGS_IF_SUPPORTED is also set.
322 * Setting SAVE_REGS_IF_SUPPORTED makes SAVE_REGS irrelevant.
324 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS &&
325 !(ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED))
326 return -EINVAL;
328 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED)
329 ops->flags |= FTRACE_OPS_FL_SAVE_REGS;
330 #endif
332 if (!core_kernel_data((unsigned long)ops))
333 ops->flags |= FTRACE_OPS_FL_DYNAMIC;
335 add_ftrace_ops(&ftrace_ops_list, ops);
337 /* Always save the function, and reset at unregistering */
338 ops->saved_func = ops->func;
340 if (ftrace_pids_enabled(ops))
341 ops->func = ftrace_pid_func;
343 ftrace_update_trampoline(ops);
345 if (ftrace_enabled)
346 update_ftrace_function();
348 return 0;
351 int __unregister_ftrace_function(struct ftrace_ops *ops)
353 int ret;
355 if (WARN_ON(!(ops->flags & FTRACE_OPS_FL_ENABLED)))
356 return -EBUSY;
358 ret = remove_ftrace_ops(&ftrace_ops_list, ops);
360 if (ret < 0)
361 return ret;
363 if (ftrace_enabled)
364 update_ftrace_function();
366 ops->func = ops->saved_func;
368 return 0;
371 static void ftrace_update_pid_func(void)
373 struct ftrace_ops *op;
375 /* Only do something if we are tracing something */
376 if (ftrace_trace_function == ftrace_stub)
377 return;
379 do_for_each_ftrace_op(op, ftrace_ops_list) {
380 if (op->flags & FTRACE_OPS_FL_PID) {
381 op->func = ftrace_pids_enabled(op) ?
382 ftrace_pid_func : op->saved_func;
383 ftrace_update_trampoline(op);
385 } while_for_each_ftrace_op(op);
387 update_ftrace_function();
390 #ifdef CONFIG_FUNCTION_PROFILER
391 struct ftrace_profile {
392 struct hlist_node node;
393 unsigned long ip;
394 unsigned long counter;
395 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
396 unsigned long long time;
397 unsigned long long time_squared;
398 #endif
401 struct ftrace_profile_page {
402 struct ftrace_profile_page *next;
403 unsigned long index;
404 struct ftrace_profile records[];
407 struct ftrace_profile_stat {
408 atomic_t disabled;
409 struct hlist_head *hash;
410 struct ftrace_profile_page *pages;
411 struct ftrace_profile_page *start;
412 struct tracer_stat stat;
415 #define PROFILE_RECORDS_SIZE \
416 (PAGE_SIZE - offsetof(struct ftrace_profile_page, records))
418 #define PROFILES_PER_PAGE \
419 (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile))
421 static int ftrace_profile_enabled __read_mostly;
423 /* ftrace_profile_lock - synchronize the enable and disable of the profiler */
424 static DEFINE_MUTEX(ftrace_profile_lock);
426 static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats);
428 #define FTRACE_PROFILE_HASH_BITS 10
429 #define FTRACE_PROFILE_HASH_SIZE (1 << FTRACE_PROFILE_HASH_BITS)
431 static void *
432 function_stat_next(void *v, int idx)
434 struct ftrace_profile *rec = v;
435 struct ftrace_profile_page *pg;
437 pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK);
439 again:
440 if (idx != 0)
441 rec++;
443 if ((void *)rec >= (void *)&pg->records[pg->index]) {
444 pg = pg->next;
445 if (!pg)
446 return NULL;
447 rec = &pg->records[0];
448 if (!rec->counter)
449 goto again;
452 return rec;
455 static void *function_stat_start(struct tracer_stat *trace)
457 struct ftrace_profile_stat *stat =
458 container_of(trace, struct ftrace_profile_stat, stat);
460 if (!stat || !stat->start)
461 return NULL;
463 return function_stat_next(&stat->start->records[0], 0);
466 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
467 /* function graph compares on total time */
468 static int function_stat_cmp(void *p1, void *p2)
470 struct ftrace_profile *a = p1;
471 struct ftrace_profile *b = p2;
473 if (a->time < b->time)
474 return -1;
475 if (a->time > b->time)
476 return 1;
477 else
478 return 0;
480 #else
481 /* not function graph compares against hits */
482 static int function_stat_cmp(void *p1, void *p2)
484 struct ftrace_profile *a = p1;
485 struct ftrace_profile *b = p2;
487 if (a->counter < b->counter)
488 return -1;
489 if (a->counter > b->counter)
490 return 1;
491 else
492 return 0;
494 #endif
496 static int function_stat_headers(struct seq_file *m)
498 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
499 seq_puts(m, " Function "
500 "Hit Time Avg s^2\n"
501 " -------- "
502 "--- ---- --- ---\n");
503 #else
504 seq_puts(m, " Function Hit\n"
505 " -------- ---\n");
506 #endif
507 return 0;
510 static int function_stat_show(struct seq_file *m, void *v)
512 struct ftrace_profile *rec = v;
513 char str[KSYM_SYMBOL_LEN];
514 int ret = 0;
515 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
516 static struct trace_seq s;
517 unsigned long long avg;
518 unsigned long long stddev;
519 #endif
520 mutex_lock(&ftrace_profile_lock);
522 /* we raced with function_profile_reset() */
523 if (unlikely(rec->counter == 0)) {
524 ret = -EBUSY;
525 goto out;
528 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
529 avg = rec->time;
530 do_div(avg, rec->counter);
531 if (tracing_thresh && (avg < tracing_thresh))
532 goto out;
533 #endif
535 kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
536 seq_printf(m, " %-30.30s %10lu", str, rec->counter);
538 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
539 seq_puts(m, " ");
541 /* Sample standard deviation (s^2) */
542 if (rec->counter <= 1)
543 stddev = 0;
544 else {
546 * Apply Welford's method:
547 * s^2 = 1 / (n * (n-1)) * (n * \Sum (x_i)^2 - (\Sum x_i)^2)
549 stddev = rec->counter * rec->time_squared -
550 rec->time * rec->time;
553 * Divide only 1000 for ns^2 -> us^2 conversion.
554 * trace_print_graph_duration will divide 1000 again.
556 do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
559 trace_seq_init(&s);
560 trace_print_graph_duration(rec->time, &s);
561 trace_seq_puts(&s, " ");
562 trace_print_graph_duration(avg, &s);
563 trace_seq_puts(&s, " ");
564 trace_print_graph_duration(stddev, &s);
565 trace_print_seq(m, &s);
566 #endif
567 seq_putc(m, '\n');
568 out:
569 mutex_unlock(&ftrace_profile_lock);
571 return ret;
574 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
576 struct ftrace_profile_page *pg;
578 pg = stat->pages = stat->start;
580 while (pg) {
581 memset(pg->records, 0, PROFILE_RECORDS_SIZE);
582 pg->index = 0;
583 pg = pg->next;
586 memset(stat->hash, 0,
587 FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head));
590 int ftrace_profile_pages_init(struct ftrace_profile_stat *stat)
592 struct ftrace_profile_page *pg;
593 int functions;
594 int pages;
595 int i;
597 /* If we already allocated, do nothing */
598 if (stat->pages)
599 return 0;
601 stat->pages = (void *)get_zeroed_page(GFP_KERNEL);
602 if (!stat->pages)
603 return -ENOMEM;
605 #ifdef CONFIG_DYNAMIC_FTRACE
606 functions = ftrace_update_tot_cnt;
607 #else
609 * We do not know the number of functions that exist because
610 * dynamic tracing is what counts them. With past experience
611 * we have around 20K functions. That should be more than enough.
612 * It is highly unlikely we will execute every function in
613 * the kernel.
615 functions = 20000;
616 #endif
618 pg = stat->start = stat->pages;
620 pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE);
622 for (i = 1; i < pages; i++) {
623 pg->next = (void *)get_zeroed_page(GFP_KERNEL);
624 if (!pg->next)
625 goto out_free;
626 pg = pg->next;
629 return 0;
631 out_free:
632 pg = stat->start;
633 while (pg) {
634 unsigned long tmp = (unsigned long)pg;
636 pg = pg->next;
637 free_page(tmp);
640 stat->pages = NULL;
641 stat->start = NULL;
643 return -ENOMEM;
646 static int ftrace_profile_init_cpu(int cpu)
648 struct ftrace_profile_stat *stat;
649 int size;
651 stat = &per_cpu(ftrace_profile_stats, cpu);
653 if (stat->hash) {
654 /* If the profile is already created, simply reset it */
655 ftrace_profile_reset(stat);
656 return 0;
660 * We are profiling all functions, but usually only a few thousand
661 * functions are hit. We'll make a hash of 1024 items.
663 size = FTRACE_PROFILE_HASH_SIZE;
665 stat->hash = kcalloc(size, sizeof(struct hlist_head), GFP_KERNEL);
667 if (!stat->hash)
668 return -ENOMEM;
670 /* Preallocate the function profiling pages */
671 if (ftrace_profile_pages_init(stat) < 0) {
672 kfree(stat->hash);
673 stat->hash = NULL;
674 return -ENOMEM;
677 return 0;
680 static int ftrace_profile_init(void)
682 int cpu;
683 int ret = 0;
685 for_each_possible_cpu(cpu) {
686 ret = ftrace_profile_init_cpu(cpu);
687 if (ret)
688 break;
691 return ret;
694 /* interrupts must be disabled */
695 static struct ftrace_profile *
696 ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip)
698 struct ftrace_profile *rec;
699 struct hlist_head *hhd;
700 unsigned long key;
702 key = hash_long(ip, FTRACE_PROFILE_HASH_BITS);
703 hhd = &stat->hash[key];
705 if (hlist_empty(hhd))
706 return NULL;
708 hlist_for_each_entry_rcu_notrace(rec, hhd, node) {
709 if (rec->ip == ip)
710 return rec;
713 return NULL;
716 static void ftrace_add_profile(struct ftrace_profile_stat *stat,
717 struct ftrace_profile *rec)
719 unsigned long key;
721 key = hash_long(rec->ip, FTRACE_PROFILE_HASH_BITS);
722 hlist_add_head_rcu(&rec->node, &stat->hash[key]);
726 * The memory is already allocated, this simply finds a new record to use.
728 static struct ftrace_profile *
729 ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip)
731 struct ftrace_profile *rec = NULL;
733 /* prevent recursion (from NMIs) */
734 if (atomic_inc_return(&stat->disabled) != 1)
735 goto out;
738 * Try to find the function again since an NMI
739 * could have added it
741 rec = ftrace_find_profiled_func(stat, ip);
742 if (rec)
743 goto out;
745 if (stat->pages->index == PROFILES_PER_PAGE) {
746 if (!stat->pages->next)
747 goto out;
748 stat->pages = stat->pages->next;
751 rec = &stat->pages->records[stat->pages->index++];
752 rec->ip = ip;
753 ftrace_add_profile(stat, rec);
755 out:
756 atomic_dec(&stat->disabled);
758 return rec;
761 static void
762 function_profile_call(unsigned long ip, unsigned long parent_ip,
763 struct ftrace_ops *ops, struct pt_regs *regs)
765 struct ftrace_profile_stat *stat;
766 struct ftrace_profile *rec;
767 unsigned long flags;
769 if (!ftrace_profile_enabled)
770 return;
772 local_irq_save(flags);
774 stat = this_cpu_ptr(&ftrace_profile_stats);
775 if (!stat->hash || !ftrace_profile_enabled)
776 goto out;
778 rec = ftrace_find_profiled_func(stat, ip);
779 if (!rec) {
780 rec = ftrace_profile_alloc(stat, ip);
781 if (!rec)
782 goto out;
785 rec->counter++;
786 out:
787 local_irq_restore(flags);
790 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
791 static bool fgraph_graph_time = true;
793 void ftrace_graph_graph_time_control(bool enable)
795 fgraph_graph_time = enable;
798 static int profile_graph_entry(struct ftrace_graph_ent *trace)
800 struct ftrace_ret_stack *ret_stack;
802 function_profile_call(trace->func, 0, NULL, NULL);
804 /* If function graph is shutting down, ret_stack can be NULL */
805 if (!current->ret_stack)
806 return 0;
808 ret_stack = ftrace_graph_get_ret_stack(current, 0);
809 if (ret_stack)
810 ret_stack->subtime = 0;
812 return 1;
815 static void profile_graph_return(struct ftrace_graph_ret *trace)
817 struct ftrace_ret_stack *ret_stack;
818 struct ftrace_profile_stat *stat;
819 unsigned long long calltime;
820 struct ftrace_profile *rec;
821 unsigned long flags;
823 local_irq_save(flags);
824 stat = this_cpu_ptr(&ftrace_profile_stats);
825 if (!stat->hash || !ftrace_profile_enabled)
826 goto out;
828 /* If the calltime was zero'd ignore it */
829 if (!trace->calltime)
830 goto out;
832 calltime = trace->rettime - trace->calltime;
834 if (!fgraph_graph_time) {
836 /* Append this call time to the parent time to subtract */
837 ret_stack = ftrace_graph_get_ret_stack(current, 1);
838 if (ret_stack)
839 ret_stack->subtime += calltime;
841 ret_stack = ftrace_graph_get_ret_stack(current, 0);
842 if (ret_stack && ret_stack->subtime < calltime)
843 calltime -= ret_stack->subtime;
844 else
845 calltime = 0;
848 rec = ftrace_find_profiled_func(stat, trace->func);
849 if (rec) {
850 rec->time += calltime;
851 rec->time_squared += calltime * calltime;
854 out:
855 local_irq_restore(flags);
858 static struct fgraph_ops fprofiler_ops = {
859 .entryfunc = &profile_graph_entry,
860 .retfunc = &profile_graph_return,
863 static int register_ftrace_profiler(void)
865 return register_ftrace_graph(&fprofiler_ops);
868 static void unregister_ftrace_profiler(void)
870 unregister_ftrace_graph(&fprofiler_ops);
872 #else
873 static struct ftrace_ops ftrace_profile_ops __read_mostly = {
874 .func = function_profile_call,
875 .flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_INITIALIZED,
876 INIT_OPS_HASH(ftrace_profile_ops)
879 static int register_ftrace_profiler(void)
881 return register_ftrace_function(&ftrace_profile_ops);
884 static void unregister_ftrace_profiler(void)
886 unregister_ftrace_function(&ftrace_profile_ops);
888 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
890 static ssize_t
891 ftrace_profile_write(struct file *filp, const char __user *ubuf,
892 size_t cnt, loff_t *ppos)
894 unsigned long val;
895 int ret;
897 ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
898 if (ret)
899 return ret;
901 val = !!val;
903 mutex_lock(&ftrace_profile_lock);
904 if (ftrace_profile_enabled ^ val) {
905 if (val) {
906 ret = ftrace_profile_init();
907 if (ret < 0) {
908 cnt = ret;
909 goto out;
912 ret = register_ftrace_profiler();
913 if (ret < 0) {
914 cnt = ret;
915 goto out;
917 ftrace_profile_enabled = 1;
918 } else {
919 ftrace_profile_enabled = 0;
921 * unregister_ftrace_profiler calls stop_machine
922 * so this acts like an synchronize_rcu.
924 unregister_ftrace_profiler();
927 out:
928 mutex_unlock(&ftrace_profile_lock);
930 *ppos += cnt;
932 return cnt;
935 static ssize_t
936 ftrace_profile_read(struct file *filp, char __user *ubuf,
937 size_t cnt, loff_t *ppos)
939 char buf[64]; /* big enough to hold a number */
940 int r;
942 r = sprintf(buf, "%u\n", ftrace_profile_enabled);
943 return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
946 static const struct file_operations ftrace_profile_fops = {
947 .open = tracing_open_generic,
948 .read = ftrace_profile_read,
949 .write = ftrace_profile_write,
950 .llseek = default_llseek,
953 /* used to initialize the real stat files */
954 static struct tracer_stat function_stats __initdata = {
955 .name = "functions",
956 .stat_start = function_stat_start,
957 .stat_next = function_stat_next,
958 .stat_cmp = function_stat_cmp,
959 .stat_headers = function_stat_headers,
960 .stat_show = function_stat_show
963 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
965 struct ftrace_profile_stat *stat;
966 struct dentry *entry;
967 char *name;
968 int ret;
969 int cpu;
971 for_each_possible_cpu(cpu) {
972 stat = &per_cpu(ftrace_profile_stats, cpu);
974 name = kasprintf(GFP_KERNEL, "function%d", cpu);
975 if (!name) {
977 * The files created are permanent, if something happens
978 * we still do not free memory.
980 WARN(1,
981 "Could not allocate stat file for cpu %d\n",
982 cpu);
983 return;
985 stat->stat = function_stats;
986 stat->stat.name = name;
987 ret = register_stat_tracer(&stat->stat);
988 if (ret) {
989 WARN(1,
990 "Could not register function stat for cpu %d\n",
991 cpu);
992 kfree(name);
993 return;
997 entry = tracefs_create_file("function_profile_enabled", 0644,
998 d_tracer, NULL, &ftrace_profile_fops);
999 if (!entry)
1000 pr_warn("Could not create tracefs 'function_profile_enabled' entry\n");
1003 #else /* CONFIG_FUNCTION_PROFILER */
1004 static __init void ftrace_profile_tracefs(struct dentry *d_tracer)
1007 #endif /* CONFIG_FUNCTION_PROFILER */
1009 #ifdef CONFIG_DYNAMIC_FTRACE
1011 static struct ftrace_ops *removed_ops;
1014 * Set when doing a global update, like enabling all recs or disabling them.
1015 * It is not set when just updating a single ftrace_ops.
1017 static bool update_all_ops;
1019 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
1020 # error Dynamic ftrace depends on MCOUNT_RECORD
1021 #endif
1023 struct ftrace_func_entry {
1024 struct hlist_node hlist;
1025 unsigned long ip;
1028 struct ftrace_func_probe {
1029 struct ftrace_probe_ops *probe_ops;
1030 struct ftrace_ops ops;
1031 struct trace_array *tr;
1032 struct list_head list;
1033 void *data;
1034 int ref;
1038 * We make these constant because no one should touch them,
1039 * but they are used as the default "empty hash", to avoid allocating
1040 * it all the time. These are in a read only section such that if
1041 * anyone does try to modify it, it will cause an exception.
1043 static const struct hlist_head empty_buckets[1];
1044 static const struct ftrace_hash empty_hash = {
1045 .buckets = (struct hlist_head *)empty_buckets,
1047 #define EMPTY_HASH ((struct ftrace_hash *)&empty_hash)
1049 struct ftrace_ops global_ops = {
1050 .func = ftrace_stub,
1051 .local_hash.notrace_hash = EMPTY_HASH,
1052 .local_hash.filter_hash = EMPTY_HASH,
1053 INIT_OPS_HASH(global_ops)
1054 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
1055 FTRACE_OPS_FL_INITIALIZED |
1056 FTRACE_OPS_FL_PID,
1060 * Used by the stack undwinder to know about dynamic ftrace trampolines.
1062 struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr)
1064 struct ftrace_ops *op = NULL;
1067 * Some of the ops may be dynamically allocated,
1068 * they are freed after a synchronize_rcu().
1070 preempt_disable_notrace();
1072 do_for_each_ftrace_op(op, ftrace_ops_list) {
1074 * This is to check for dynamically allocated trampolines.
1075 * Trampolines that are in kernel text will have
1076 * core_kernel_text() return true.
1078 if (op->trampoline && op->trampoline_size)
1079 if (addr >= op->trampoline &&
1080 addr < op->trampoline + op->trampoline_size) {
1081 preempt_enable_notrace();
1082 return op;
1084 } while_for_each_ftrace_op(op);
1085 preempt_enable_notrace();
1087 return NULL;
1091 * This is used by __kernel_text_address() to return true if the
1092 * address is on a dynamically allocated trampoline that would
1093 * not return true for either core_kernel_text() or
1094 * is_module_text_address().
1096 bool is_ftrace_trampoline(unsigned long addr)
1098 return ftrace_ops_trampoline(addr) != NULL;
1101 struct ftrace_page {
1102 struct ftrace_page *next;
1103 struct dyn_ftrace *records;
1104 int index;
1105 int size;
1108 #define ENTRY_SIZE sizeof(struct dyn_ftrace)
1109 #define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
1111 /* estimate from running different kernels */
1112 #define NR_TO_INIT 10000
1114 static struct ftrace_page *ftrace_pages_start;
1115 static struct ftrace_page *ftrace_pages;
1117 static __always_inline unsigned long
1118 ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
1120 if (hash->size_bits > 0)
1121 return hash_long(ip, hash->size_bits);
1123 return 0;
1126 /* Only use this function if ftrace_hash_empty() has already been tested */
1127 static __always_inline struct ftrace_func_entry *
1128 __ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1130 unsigned long key;
1131 struct ftrace_func_entry *entry;
1132 struct hlist_head *hhd;
1134 key = ftrace_hash_key(hash, ip);
1135 hhd = &hash->buckets[key];
1137 hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
1138 if (entry->ip == ip)
1139 return entry;
1141 return NULL;
1145 * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
1146 * @hash: The hash to look at
1147 * @ip: The instruction pointer to test
1149 * Search a given @hash to see if a given instruction pointer (@ip)
1150 * exists in it.
1152 * Returns the entry that holds the @ip if found. NULL otherwise.
1154 struct ftrace_func_entry *
1155 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
1157 if (ftrace_hash_empty(hash))
1158 return NULL;
1160 return __ftrace_lookup_ip(hash, ip);
1163 static void __add_hash_entry(struct ftrace_hash *hash,
1164 struct ftrace_func_entry *entry)
1166 struct hlist_head *hhd;
1167 unsigned long key;
1169 key = ftrace_hash_key(hash, entry->ip);
1170 hhd = &hash->buckets[key];
1171 hlist_add_head(&entry->hlist, hhd);
1172 hash->count++;
1175 static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
1177 struct ftrace_func_entry *entry;
1179 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1180 if (!entry)
1181 return -ENOMEM;
1183 entry->ip = ip;
1184 __add_hash_entry(hash, entry);
1186 return 0;
1189 static void
1190 free_hash_entry(struct ftrace_hash *hash,
1191 struct ftrace_func_entry *entry)
1193 hlist_del(&entry->hlist);
1194 kfree(entry);
1195 hash->count--;
1198 static void
1199 remove_hash_entry(struct ftrace_hash *hash,
1200 struct ftrace_func_entry *entry)
1202 hlist_del_rcu(&entry->hlist);
1203 hash->count--;
1206 static void ftrace_hash_clear(struct ftrace_hash *hash)
1208 struct hlist_head *hhd;
1209 struct hlist_node *tn;
1210 struct ftrace_func_entry *entry;
1211 int size = 1 << hash->size_bits;
1212 int i;
1214 if (!hash->count)
1215 return;
1217 for (i = 0; i < size; i++) {
1218 hhd = &hash->buckets[i];
1219 hlist_for_each_entry_safe(entry, tn, hhd, hlist)
1220 free_hash_entry(hash, entry);
1222 FTRACE_WARN_ON(hash->count);
1225 static void free_ftrace_mod(struct ftrace_mod_load *ftrace_mod)
1227 list_del(&ftrace_mod->list);
1228 kfree(ftrace_mod->module);
1229 kfree(ftrace_mod->func);
1230 kfree(ftrace_mod);
1233 static void clear_ftrace_mod_list(struct list_head *head)
1235 struct ftrace_mod_load *p, *n;
1237 /* stack tracer isn't supported yet */
1238 if (!head)
1239 return;
1241 mutex_lock(&ftrace_lock);
1242 list_for_each_entry_safe(p, n, head, list)
1243 free_ftrace_mod(p);
1244 mutex_unlock(&ftrace_lock);
1247 static void free_ftrace_hash(struct ftrace_hash *hash)
1249 if (!hash || hash == EMPTY_HASH)
1250 return;
1251 ftrace_hash_clear(hash);
1252 kfree(hash->buckets);
1253 kfree(hash);
1256 static void __free_ftrace_hash_rcu(struct rcu_head *rcu)
1258 struct ftrace_hash *hash;
1260 hash = container_of(rcu, struct ftrace_hash, rcu);
1261 free_ftrace_hash(hash);
1264 static void free_ftrace_hash_rcu(struct ftrace_hash *hash)
1266 if (!hash || hash == EMPTY_HASH)
1267 return;
1268 call_rcu(&hash->rcu, __free_ftrace_hash_rcu);
1271 void ftrace_free_filter(struct ftrace_ops *ops)
1273 ftrace_ops_init(ops);
1274 free_ftrace_hash(ops->func_hash->filter_hash);
1275 free_ftrace_hash(ops->func_hash->notrace_hash);
1278 static struct ftrace_hash *alloc_ftrace_hash(int size_bits)
1280 struct ftrace_hash *hash;
1281 int size;
1283 hash = kzalloc(sizeof(*hash), GFP_KERNEL);
1284 if (!hash)
1285 return NULL;
1287 size = 1 << size_bits;
1288 hash->buckets = kcalloc(size, sizeof(*hash->buckets), GFP_KERNEL);
1290 if (!hash->buckets) {
1291 kfree(hash);
1292 return NULL;
1295 hash->size_bits = size_bits;
1297 return hash;
1301 static int ftrace_add_mod(struct trace_array *tr,
1302 const char *func, const char *module,
1303 int enable)
1305 struct ftrace_mod_load *ftrace_mod;
1306 struct list_head *mod_head = enable ? &tr->mod_trace : &tr->mod_notrace;
1308 ftrace_mod = kzalloc(sizeof(*ftrace_mod), GFP_KERNEL);
1309 if (!ftrace_mod)
1310 return -ENOMEM;
1312 ftrace_mod->func = kstrdup(func, GFP_KERNEL);
1313 ftrace_mod->module = kstrdup(module, GFP_KERNEL);
1314 ftrace_mod->enable = enable;
1316 if (!ftrace_mod->func || !ftrace_mod->module)
1317 goto out_free;
1319 list_add(&ftrace_mod->list, mod_head);
1321 return 0;
1323 out_free:
1324 free_ftrace_mod(ftrace_mod);
1326 return -ENOMEM;
1329 static struct ftrace_hash *
1330 alloc_and_copy_ftrace_hash(int size_bits, struct ftrace_hash *hash)
1332 struct ftrace_func_entry *entry;
1333 struct ftrace_hash *new_hash;
1334 int size;
1335 int ret;
1336 int i;
1338 new_hash = alloc_ftrace_hash(size_bits);
1339 if (!new_hash)
1340 return NULL;
1342 if (hash)
1343 new_hash->flags = hash->flags;
1345 /* Empty hash? */
1346 if (ftrace_hash_empty(hash))
1347 return new_hash;
1349 size = 1 << hash->size_bits;
1350 for (i = 0; i < size; i++) {
1351 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
1352 ret = add_hash_entry(new_hash, entry->ip);
1353 if (ret < 0)
1354 goto free_hash;
1358 FTRACE_WARN_ON(new_hash->count != hash->count);
1360 return new_hash;
1362 free_hash:
1363 free_ftrace_hash(new_hash);
1364 return NULL;
1367 static void
1368 ftrace_hash_rec_disable_modify(struct ftrace_ops *ops, int filter_hash);
1369 static void
1370 ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
1372 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1373 struct ftrace_hash *new_hash);
1375 static struct ftrace_hash *
1376 __ftrace_hash_move(struct ftrace_hash *src)
1378 struct ftrace_func_entry *entry;
1379 struct hlist_node *tn;
1380 struct hlist_head *hhd;
1381 struct ftrace_hash *new_hash;
1382 int size = src->count;
1383 int bits = 0;
1384 int i;
1387 * If the new source is empty, just return the empty_hash.
1389 if (ftrace_hash_empty(src))
1390 return EMPTY_HASH;
1393 * Make the hash size about 1/2 the # found
1395 for (size /= 2; size; size >>= 1)
1396 bits++;
1398 /* Don't allocate too much */
1399 if (bits > FTRACE_HASH_MAX_BITS)
1400 bits = FTRACE_HASH_MAX_BITS;
1402 new_hash = alloc_ftrace_hash(bits);
1403 if (!new_hash)
1404 return NULL;
1406 new_hash->flags = src->flags;
1408 size = 1 << src->size_bits;
1409 for (i = 0; i < size; i++) {
1410 hhd = &src->buckets[i];
1411 hlist_for_each_entry_safe(entry, tn, hhd, hlist) {
1412 remove_hash_entry(src, entry);
1413 __add_hash_entry(new_hash, entry);
1417 return new_hash;
1420 static int
1421 ftrace_hash_move(struct ftrace_ops *ops, int enable,
1422 struct ftrace_hash **dst, struct ftrace_hash *src)
1424 struct ftrace_hash *new_hash;
1425 int ret;
1427 /* Reject setting notrace hash on IPMODIFY ftrace_ops */
1428 if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
1429 return -EINVAL;
1431 new_hash = __ftrace_hash_move(src);
1432 if (!new_hash)
1433 return -ENOMEM;
1435 /* Make sure this can be applied if it is IPMODIFY ftrace_ops */
1436 if (enable) {
1437 /* IPMODIFY should be updated only when filter_hash updating */
1438 ret = ftrace_hash_ipmodify_update(ops, new_hash);
1439 if (ret < 0) {
1440 free_ftrace_hash(new_hash);
1441 return ret;
1446 * Remove the current set, update the hash and add
1447 * them back.
1449 ftrace_hash_rec_disable_modify(ops, enable);
1451 rcu_assign_pointer(*dst, new_hash);
1453 ftrace_hash_rec_enable_modify(ops, enable);
1455 return 0;
1458 static bool hash_contains_ip(unsigned long ip,
1459 struct ftrace_ops_hash *hash)
1462 * The function record is a match if it exists in the filter
1463 * hash and not in the notrace hash. Note, an emty hash is
1464 * considered a match for the filter hash, but an empty
1465 * notrace hash is considered not in the notrace hash.
1467 return (ftrace_hash_empty(hash->filter_hash) ||
1468 __ftrace_lookup_ip(hash->filter_hash, ip)) &&
1469 (ftrace_hash_empty(hash->notrace_hash) ||
1470 !__ftrace_lookup_ip(hash->notrace_hash, ip));
1474 * Test the hashes for this ops to see if we want to call
1475 * the ops->func or not.
1477 * It's a match if the ip is in the ops->filter_hash or
1478 * the filter_hash does not exist or is empty,
1479 * AND
1480 * the ip is not in the ops->notrace_hash.
1482 * This needs to be called with preemption disabled as
1483 * the hashes are freed with call_rcu().
1486 ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
1488 struct ftrace_ops_hash hash;
1489 int ret;
1491 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
1493 * There's a small race when adding ops that the ftrace handler
1494 * that wants regs, may be called without them. We can not
1495 * allow that handler to be called if regs is NULL.
1497 if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
1498 return 0;
1499 #endif
1501 rcu_assign_pointer(hash.filter_hash, ops->func_hash->filter_hash);
1502 rcu_assign_pointer(hash.notrace_hash, ops->func_hash->notrace_hash);
1504 if (hash_contains_ip(ip, &hash))
1505 ret = 1;
1506 else
1507 ret = 0;
1509 return ret;
1513 * This is a double for. Do not use 'break' to break out of the loop,
1514 * you must use a goto.
1516 #define do_for_each_ftrace_rec(pg, rec) \
1517 for (pg = ftrace_pages_start; pg; pg = pg->next) { \
1518 int _____i; \
1519 for (_____i = 0; _____i < pg->index; _____i++) { \
1520 rec = &pg->records[_____i];
1522 #define while_for_each_ftrace_rec() \
1527 static int ftrace_cmp_recs(const void *a, const void *b)
1529 const struct dyn_ftrace *key = a;
1530 const struct dyn_ftrace *rec = b;
1532 if (key->flags < rec->ip)
1533 return -1;
1534 if (key->ip >= rec->ip + MCOUNT_INSN_SIZE)
1535 return 1;
1536 return 0;
1540 * ftrace_location_range - return the first address of a traced location
1541 * if it touches the given ip range
1542 * @start: start of range to search.
1543 * @end: end of range to search (inclusive). @end points to the last byte
1544 * to check.
1546 * Returns rec->ip if the related ftrace location is a least partly within
1547 * the given address range. That is, the first address of the instruction
1548 * that is either a NOP or call to the function tracer. It checks the ftrace
1549 * internal tables to determine if the address belongs or not.
1551 unsigned long ftrace_location_range(unsigned long start, unsigned long end)
1553 struct ftrace_page *pg;
1554 struct dyn_ftrace *rec;
1555 struct dyn_ftrace key;
1557 key.ip = start;
1558 key.flags = end; /* overload flags, as it is unsigned long */
1560 for (pg = ftrace_pages_start; pg; pg = pg->next) {
1561 if (end < pg->records[0].ip ||
1562 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
1563 continue;
1564 rec = bsearch(&key, pg->records, pg->index,
1565 sizeof(struct dyn_ftrace),
1566 ftrace_cmp_recs);
1567 if (rec)
1568 return rec->ip;
1571 return 0;
1575 * ftrace_location - return true if the ip giving is a traced location
1576 * @ip: the instruction pointer to check
1578 * Returns rec->ip if @ip given is a pointer to a ftrace location.
1579 * That is, the instruction that is either a NOP or call to
1580 * the function tracer. It checks the ftrace internal tables to
1581 * determine if the address belongs or not.
1583 unsigned long ftrace_location(unsigned long ip)
1585 return ftrace_location_range(ip, ip);
1589 * ftrace_text_reserved - return true if range contains an ftrace location
1590 * @start: start of range to search
1591 * @end: end of range to search (inclusive). @end points to the last byte to check.
1593 * Returns 1 if @start and @end contains a ftrace location.
1594 * That is, the instruction that is either a NOP or call to
1595 * the function tracer. It checks the ftrace internal tables to
1596 * determine if the address belongs or not.
1598 int ftrace_text_reserved(const void *start, const void *end)
1600 unsigned long ret;
1602 ret = ftrace_location_range((unsigned long)start,
1603 (unsigned long)end);
1605 return (int)!!ret;
1608 /* Test if ops registered to this rec needs regs */
1609 static bool test_rec_ops_needs_regs(struct dyn_ftrace *rec)
1611 struct ftrace_ops *ops;
1612 bool keep_regs = false;
1614 for (ops = ftrace_ops_list;
1615 ops != &ftrace_list_end; ops = ops->next) {
1616 /* pass rec in as regs to have non-NULL val */
1617 if (ftrace_ops_test(ops, rec->ip, rec)) {
1618 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1619 keep_regs = true;
1620 break;
1625 return keep_regs;
1628 static bool __ftrace_hash_rec_update(struct ftrace_ops *ops,
1629 int filter_hash,
1630 bool inc)
1632 struct ftrace_hash *hash;
1633 struct ftrace_hash *other_hash;
1634 struct ftrace_page *pg;
1635 struct dyn_ftrace *rec;
1636 bool update = false;
1637 int count = 0;
1638 int all = false;
1640 /* Only update if the ops has been registered */
1641 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1642 return false;
1645 * In the filter_hash case:
1646 * If the count is zero, we update all records.
1647 * Otherwise we just update the items in the hash.
1649 * In the notrace_hash case:
1650 * We enable the update in the hash.
1651 * As disabling notrace means enabling the tracing,
1652 * and enabling notrace means disabling, the inc variable
1653 * gets inversed.
1655 if (filter_hash) {
1656 hash = ops->func_hash->filter_hash;
1657 other_hash = ops->func_hash->notrace_hash;
1658 if (ftrace_hash_empty(hash))
1659 all = true;
1660 } else {
1661 inc = !inc;
1662 hash = ops->func_hash->notrace_hash;
1663 other_hash = ops->func_hash->filter_hash;
1665 * If the notrace hash has no items,
1666 * then there's nothing to do.
1668 if (ftrace_hash_empty(hash))
1669 return false;
1672 do_for_each_ftrace_rec(pg, rec) {
1673 int in_other_hash = 0;
1674 int in_hash = 0;
1675 int match = 0;
1677 if (rec->flags & FTRACE_FL_DISABLED)
1678 continue;
1680 if (all) {
1682 * Only the filter_hash affects all records.
1683 * Update if the record is not in the notrace hash.
1685 if (!other_hash || !ftrace_lookup_ip(other_hash, rec->ip))
1686 match = 1;
1687 } else {
1688 in_hash = !!ftrace_lookup_ip(hash, rec->ip);
1689 in_other_hash = !!ftrace_lookup_ip(other_hash, rec->ip);
1692 * If filter_hash is set, we want to match all functions
1693 * that are in the hash but not in the other hash.
1695 * If filter_hash is not set, then we are decrementing.
1696 * That means we match anything that is in the hash
1697 * and also in the other_hash. That is, we need to turn
1698 * off functions in the other hash because they are disabled
1699 * by this hash.
1701 if (filter_hash && in_hash && !in_other_hash)
1702 match = 1;
1703 else if (!filter_hash && in_hash &&
1704 (in_other_hash || ftrace_hash_empty(other_hash)))
1705 match = 1;
1707 if (!match)
1708 continue;
1710 if (inc) {
1711 rec->flags++;
1712 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == FTRACE_REF_MAX))
1713 return false;
1716 * If there's only a single callback registered to a
1717 * function, and the ops has a trampoline registered
1718 * for it, then we can call it directly.
1720 if (ftrace_rec_count(rec) == 1 && ops->trampoline)
1721 rec->flags |= FTRACE_FL_TRAMP;
1722 else
1724 * If we are adding another function callback
1725 * to this function, and the previous had a
1726 * custom trampoline in use, then we need to go
1727 * back to the default trampoline.
1729 rec->flags &= ~FTRACE_FL_TRAMP;
1732 * If any ops wants regs saved for this function
1733 * then all ops will get saved regs.
1735 if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
1736 rec->flags |= FTRACE_FL_REGS;
1737 } else {
1738 if (FTRACE_WARN_ON(ftrace_rec_count(rec) == 0))
1739 return false;
1740 rec->flags--;
1743 * If the rec had REGS enabled and the ops that is
1744 * being removed had REGS set, then see if there is
1745 * still any ops for this record that wants regs.
1746 * If not, we can stop recording them.
1748 if (ftrace_rec_count(rec) > 0 &&
1749 rec->flags & FTRACE_FL_REGS &&
1750 ops->flags & FTRACE_OPS_FL_SAVE_REGS) {
1751 if (!test_rec_ops_needs_regs(rec))
1752 rec->flags &= ~FTRACE_FL_REGS;
1756 * If the rec had TRAMP enabled, then it needs to
1757 * be cleared. As TRAMP can only be enabled iff
1758 * there is only a single ops attached to it.
1759 * In otherwords, always disable it on decrementing.
1760 * In the future, we may set it if rec count is
1761 * decremented to one, and the ops that is left
1762 * has a trampoline.
1764 rec->flags &= ~FTRACE_FL_TRAMP;
1767 * flags will be cleared in ftrace_check_record()
1768 * if rec count is zero.
1771 count++;
1773 /* Must match FTRACE_UPDATE_CALLS in ftrace_modify_all_code() */
1774 update |= ftrace_test_record(rec, 1) != FTRACE_UPDATE_IGNORE;
1776 /* Shortcut, if we handled all records, we are done. */
1777 if (!all && count == hash->count)
1778 return update;
1779 } while_for_each_ftrace_rec();
1781 return update;
1784 static bool ftrace_hash_rec_disable(struct ftrace_ops *ops,
1785 int filter_hash)
1787 return __ftrace_hash_rec_update(ops, filter_hash, 0);
1790 static bool ftrace_hash_rec_enable(struct ftrace_ops *ops,
1791 int filter_hash)
1793 return __ftrace_hash_rec_update(ops, filter_hash, 1);
1796 static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops,
1797 int filter_hash, int inc)
1799 struct ftrace_ops *op;
1801 __ftrace_hash_rec_update(ops, filter_hash, inc);
1803 if (ops->func_hash != &global_ops.local_hash)
1804 return;
1807 * If the ops shares the global_ops hash, then we need to update
1808 * all ops that are enabled and use this hash.
1810 do_for_each_ftrace_op(op, ftrace_ops_list) {
1811 /* Already done */
1812 if (op == ops)
1813 continue;
1814 if (op->func_hash == &global_ops.local_hash)
1815 __ftrace_hash_rec_update(op, filter_hash, inc);
1816 } while_for_each_ftrace_op(op);
1819 static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops,
1820 int filter_hash)
1822 ftrace_hash_rec_update_modify(ops, filter_hash, 0);
1825 static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops,
1826 int filter_hash)
1828 ftrace_hash_rec_update_modify(ops, filter_hash, 1);
1832 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK
1833 * or no-needed to update, -EBUSY if it detects a conflict of the flag
1834 * on a ftrace_rec, and -EINVAL if the new_hash tries to trace all recs.
1835 * Note that old_hash and new_hash has below meanings
1836 * - If the hash is NULL, it hits all recs (if IPMODIFY is set, this is rejected)
1837 * - If the hash is EMPTY_HASH, it hits nothing
1838 * - Anything else hits the recs which match the hash entries.
1840 static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
1841 struct ftrace_hash *old_hash,
1842 struct ftrace_hash *new_hash)
1844 struct ftrace_page *pg;
1845 struct dyn_ftrace *rec, *end = NULL;
1846 int in_old, in_new;
1848 /* Only update if the ops has been registered */
1849 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
1850 return 0;
1852 if (!(ops->flags & FTRACE_OPS_FL_IPMODIFY))
1853 return 0;
1856 * Since the IPMODIFY is a very address sensitive action, we do not
1857 * allow ftrace_ops to set all functions to new hash.
1859 if (!new_hash || !old_hash)
1860 return -EINVAL;
1862 /* Update rec->flags */
1863 do_for_each_ftrace_rec(pg, rec) {
1865 if (rec->flags & FTRACE_FL_DISABLED)
1866 continue;
1868 /* We need to update only differences of filter_hash */
1869 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1870 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1871 if (in_old == in_new)
1872 continue;
1874 if (in_new) {
1875 /* New entries must ensure no others are using it */
1876 if (rec->flags & FTRACE_FL_IPMODIFY)
1877 goto rollback;
1878 rec->flags |= FTRACE_FL_IPMODIFY;
1879 } else /* Removed entry */
1880 rec->flags &= ~FTRACE_FL_IPMODIFY;
1881 } while_for_each_ftrace_rec();
1883 return 0;
1885 rollback:
1886 end = rec;
1888 /* Roll back what we did above */
1889 do_for_each_ftrace_rec(pg, rec) {
1891 if (rec->flags & FTRACE_FL_DISABLED)
1892 continue;
1894 if (rec == end)
1895 goto err_out;
1897 in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
1898 in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
1899 if (in_old == in_new)
1900 continue;
1902 if (in_new)
1903 rec->flags &= ~FTRACE_FL_IPMODIFY;
1904 else
1905 rec->flags |= FTRACE_FL_IPMODIFY;
1906 } while_for_each_ftrace_rec();
1908 err_out:
1909 return -EBUSY;
1912 static int ftrace_hash_ipmodify_enable(struct ftrace_ops *ops)
1914 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1916 if (ftrace_hash_empty(hash))
1917 hash = NULL;
1919 return __ftrace_hash_update_ipmodify(ops, EMPTY_HASH, hash);
1922 /* Disabling always succeeds */
1923 static void ftrace_hash_ipmodify_disable(struct ftrace_ops *ops)
1925 struct ftrace_hash *hash = ops->func_hash->filter_hash;
1927 if (ftrace_hash_empty(hash))
1928 hash = NULL;
1930 __ftrace_hash_update_ipmodify(ops, hash, EMPTY_HASH);
1933 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
1934 struct ftrace_hash *new_hash)
1936 struct ftrace_hash *old_hash = ops->func_hash->filter_hash;
1938 if (ftrace_hash_empty(old_hash))
1939 old_hash = NULL;
1941 if (ftrace_hash_empty(new_hash))
1942 new_hash = NULL;
1944 return __ftrace_hash_update_ipmodify(ops, old_hash, new_hash);
1947 static void print_ip_ins(const char *fmt, const unsigned char *p)
1949 int i;
1951 printk(KERN_CONT "%s", fmt);
1953 for (i = 0; i < MCOUNT_INSN_SIZE; i++)
1954 printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
1957 static struct ftrace_ops *
1958 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec);
1959 static struct ftrace_ops *
1960 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops);
1962 enum ftrace_bug_type ftrace_bug_type;
1963 const void *ftrace_expected;
1965 static void print_bug_type(void)
1967 switch (ftrace_bug_type) {
1968 case FTRACE_BUG_UNKNOWN:
1969 break;
1970 case FTRACE_BUG_INIT:
1971 pr_info("Initializing ftrace call sites\n");
1972 break;
1973 case FTRACE_BUG_NOP:
1974 pr_info("Setting ftrace call site to NOP\n");
1975 break;
1976 case FTRACE_BUG_CALL:
1977 pr_info("Setting ftrace call site to call ftrace function\n");
1978 break;
1979 case FTRACE_BUG_UPDATE:
1980 pr_info("Updating ftrace call site to call a different ftrace function\n");
1981 break;
1986 * ftrace_bug - report and shutdown function tracer
1987 * @failed: The failed type (EFAULT, EINVAL, EPERM)
1988 * @rec: The record that failed
1990 * The arch code that enables or disables the function tracing
1991 * can call ftrace_bug() when it has detected a problem in
1992 * modifying the code. @failed should be one of either:
1993 * EFAULT - if the problem happens on reading the @ip address
1994 * EINVAL - if what is read at @ip is not what was expected
1995 * EPERM - if the problem happens on writting to the @ip address
1997 void ftrace_bug(int failed, struct dyn_ftrace *rec)
1999 unsigned long ip = rec ? rec->ip : 0;
2001 switch (failed) {
2002 case -EFAULT:
2003 FTRACE_WARN_ON_ONCE(1);
2004 pr_info("ftrace faulted on modifying ");
2005 print_ip_sym(ip);
2006 break;
2007 case -EINVAL:
2008 FTRACE_WARN_ON_ONCE(1);
2009 pr_info("ftrace failed to modify ");
2010 print_ip_sym(ip);
2011 print_ip_ins(" actual: ", (unsigned char *)ip);
2012 pr_cont("\n");
2013 if (ftrace_expected) {
2014 print_ip_ins(" expected: ", ftrace_expected);
2015 pr_cont("\n");
2017 break;
2018 case -EPERM:
2019 FTRACE_WARN_ON_ONCE(1);
2020 pr_info("ftrace faulted on writing ");
2021 print_ip_sym(ip);
2022 break;
2023 default:
2024 FTRACE_WARN_ON_ONCE(1);
2025 pr_info("ftrace faulted on unknown error ");
2026 print_ip_sym(ip);
2028 print_bug_type();
2029 if (rec) {
2030 struct ftrace_ops *ops = NULL;
2032 pr_info("ftrace record flags: %lx\n", rec->flags);
2033 pr_cont(" (%ld)%s", ftrace_rec_count(rec),
2034 rec->flags & FTRACE_FL_REGS ? " R" : " ");
2035 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2036 ops = ftrace_find_tramp_ops_any(rec);
2037 if (ops) {
2038 do {
2039 pr_cont("\ttramp: %pS (%pS)",
2040 (void *)ops->trampoline,
2041 (void *)ops->func);
2042 ops = ftrace_find_tramp_ops_next(rec, ops);
2043 } while (ops);
2044 } else
2045 pr_cont("\ttramp: ERROR!");
2048 ip = ftrace_get_addr_curr(rec);
2049 pr_cont("\n expected tramp: %lx\n", ip);
2053 static int ftrace_check_record(struct dyn_ftrace *rec, int enable, int update)
2055 unsigned long flag = 0UL;
2057 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2059 if (rec->flags & FTRACE_FL_DISABLED)
2060 return FTRACE_UPDATE_IGNORE;
2063 * If we are updating calls:
2065 * If the record has a ref count, then we need to enable it
2066 * because someone is using it.
2068 * Otherwise we make sure its disabled.
2070 * If we are disabling calls, then disable all records that
2071 * are enabled.
2073 if (enable && ftrace_rec_count(rec))
2074 flag = FTRACE_FL_ENABLED;
2077 * If enabling and the REGS flag does not match the REGS_EN, or
2078 * the TRAMP flag doesn't match the TRAMP_EN, then do not ignore
2079 * this record. Set flags to fail the compare against ENABLED.
2081 if (flag) {
2082 if (!(rec->flags & FTRACE_FL_REGS) !=
2083 !(rec->flags & FTRACE_FL_REGS_EN))
2084 flag |= FTRACE_FL_REGS;
2086 if (!(rec->flags & FTRACE_FL_TRAMP) !=
2087 !(rec->flags & FTRACE_FL_TRAMP_EN))
2088 flag |= FTRACE_FL_TRAMP;
2091 /* If the state of this record hasn't changed, then do nothing */
2092 if ((rec->flags & FTRACE_FL_ENABLED) == flag)
2093 return FTRACE_UPDATE_IGNORE;
2095 if (flag) {
2096 /* Save off if rec is being enabled (for return value) */
2097 flag ^= rec->flags & FTRACE_FL_ENABLED;
2099 if (update) {
2100 rec->flags |= FTRACE_FL_ENABLED;
2101 if (flag & FTRACE_FL_REGS) {
2102 if (rec->flags & FTRACE_FL_REGS)
2103 rec->flags |= FTRACE_FL_REGS_EN;
2104 else
2105 rec->flags &= ~FTRACE_FL_REGS_EN;
2107 if (flag & FTRACE_FL_TRAMP) {
2108 if (rec->flags & FTRACE_FL_TRAMP)
2109 rec->flags |= FTRACE_FL_TRAMP_EN;
2110 else
2111 rec->flags &= ~FTRACE_FL_TRAMP_EN;
2116 * If this record is being updated from a nop, then
2117 * return UPDATE_MAKE_CALL.
2118 * Otherwise,
2119 * return UPDATE_MODIFY_CALL to tell the caller to convert
2120 * from the save regs, to a non-save regs function or
2121 * vice versa, or from a trampoline call.
2123 if (flag & FTRACE_FL_ENABLED) {
2124 ftrace_bug_type = FTRACE_BUG_CALL;
2125 return FTRACE_UPDATE_MAKE_CALL;
2128 ftrace_bug_type = FTRACE_BUG_UPDATE;
2129 return FTRACE_UPDATE_MODIFY_CALL;
2132 if (update) {
2133 /* If there's no more users, clear all flags */
2134 if (!ftrace_rec_count(rec))
2135 rec->flags = 0;
2136 else
2138 * Just disable the record, but keep the ops TRAMP
2139 * and REGS states. The _EN flags must be disabled though.
2141 rec->flags &= ~(FTRACE_FL_ENABLED | FTRACE_FL_TRAMP_EN |
2142 FTRACE_FL_REGS_EN);
2145 ftrace_bug_type = FTRACE_BUG_NOP;
2146 return FTRACE_UPDATE_MAKE_NOP;
2150 * ftrace_update_record, set a record that now is tracing or not
2151 * @rec: the record to update
2152 * @enable: set to 1 if the record is tracing, zero to force disable
2154 * The records that represent all functions that can be traced need
2155 * to be updated when tracing has been enabled.
2157 int ftrace_update_record(struct dyn_ftrace *rec, int enable)
2159 return ftrace_check_record(rec, enable, 1);
2163 * ftrace_test_record, check if the record has been enabled or not
2164 * @rec: the record to test
2165 * @enable: set to 1 to check if enabled, 0 if it is disabled
2167 * The arch code may need to test if a record is already set to
2168 * tracing to determine how to modify the function code that it
2169 * represents.
2171 int ftrace_test_record(struct dyn_ftrace *rec, int enable)
2173 return ftrace_check_record(rec, enable, 0);
2176 static struct ftrace_ops *
2177 ftrace_find_tramp_ops_any(struct dyn_ftrace *rec)
2179 struct ftrace_ops *op;
2180 unsigned long ip = rec->ip;
2182 do_for_each_ftrace_op(op, ftrace_ops_list) {
2184 if (!op->trampoline)
2185 continue;
2187 if (hash_contains_ip(ip, op->func_hash))
2188 return op;
2189 } while_for_each_ftrace_op(op);
2191 return NULL;
2194 static struct ftrace_ops *
2195 ftrace_find_tramp_ops_next(struct dyn_ftrace *rec,
2196 struct ftrace_ops *op)
2198 unsigned long ip = rec->ip;
2200 while_for_each_ftrace_op(op) {
2202 if (!op->trampoline)
2203 continue;
2205 if (hash_contains_ip(ip, op->func_hash))
2206 return op;
2209 return NULL;
2212 static struct ftrace_ops *
2213 ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec)
2215 struct ftrace_ops *op;
2216 unsigned long ip = rec->ip;
2219 * Need to check removed ops first.
2220 * If they are being removed, and this rec has a tramp,
2221 * and this rec is in the ops list, then it would be the
2222 * one with the tramp.
2224 if (removed_ops) {
2225 if (hash_contains_ip(ip, &removed_ops->old_hash))
2226 return removed_ops;
2230 * Need to find the current trampoline for a rec.
2231 * Now, a trampoline is only attached to a rec if there
2232 * was a single 'ops' attached to it. But this can be called
2233 * when we are adding another op to the rec or removing the
2234 * current one. Thus, if the op is being added, we can
2235 * ignore it because it hasn't attached itself to the rec
2236 * yet.
2238 * If an ops is being modified (hooking to different functions)
2239 * then we don't care about the new functions that are being
2240 * added, just the old ones (that are probably being removed).
2242 * If we are adding an ops to a function that already is using
2243 * a trampoline, it needs to be removed (trampolines are only
2244 * for single ops connected), then an ops that is not being
2245 * modified also needs to be checked.
2247 do_for_each_ftrace_op(op, ftrace_ops_list) {
2249 if (!op->trampoline)
2250 continue;
2253 * If the ops is being added, it hasn't gotten to
2254 * the point to be removed from this tree yet.
2256 if (op->flags & FTRACE_OPS_FL_ADDING)
2257 continue;
2261 * If the ops is being modified and is in the old
2262 * hash, then it is probably being removed from this
2263 * function.
2265 if ((op->flags & FTRACE_OPS_FL_MODIFYING) &&
2266 hash_contains_ip(ip, &op->old_hash))
2267 return op;
2269 * If the ops is not being added or modified, and it's
2270 * in its normal filter hash, then this must be the one
2271 * we want!
2273 if (!(op->flags & FTRACE_OPS_FL_MODIFYING) &&
2274 hash_contains_ip(ip, op->func_hash))
2275 return op;
2277 } while_for_each_ftrace_op(op);
2279 return NULL;
2282 static struct ftrace_ops *
2283 ftrace_find_tramp_ops_new(struct dyn_ftrace *rec)
2285 struct ftrace_ops *op;
2286 unsigned long ip = rec->ip;
2288 do_for_each_ftrace_op(op, ftrace_ops_list) {
2289 /* pass rec in as regs to have non-NULL val */
2290 if (hash_contains_ip(ip, op->func_hash))
2291 return op;
2292 } while_for_each_ftrace_op(op);
2294 return NULL;
2298 * ftrace_get_addr_new - Get the call address to set to
2299 * @rec: The ftrace record descriptor
2301 * If the record has the FTRACE_FL_REGS set, that means that it
2302 * wants to convert to a callback that saves all regs. If FTRACE_FL_REGS
2303 * is not not set, then it wants to convert to the normal callback.
2305 * Returns the address of the trampoline to set to
2307 unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec)
2309 struct ftrace_ops *ops;
2311 /* Trampolines take precedence over regs */
2312 if (rec->flags & FTRACE_FL_TRAMP) {
2313 ops = ftrace_find_tramp_ops_new(rec);
2314 if (FTRACE_WARN_ON(!ops || !ops->trampoline)) {
2315 pr_warn("Bad trampoline accounting at: %p (%pS) (%lx)\n",
2316 (void *)rec->ip, (void *)rec->ip, rec->flags);
2317 /* Ftrace is shutting down, return anything */
2318 return (unsigned long)FTRACE_ADDR;
2320 return ops->trampoline;
2323 if (rec->flags & FTRACE_FL_REGS)
2324 return (unsigned long)FTRACE_REGS_ADDR;
2325 else
2326 return (unsigned long)FTRACE_ADDR;
2330 * ftrace_get_addr_curr - Get the call address that is already there
2331 * @rec: The ftrace record descriptor
2333 * The FTRACE_FL_REGS_EN is set when the record already points to
2334 * a function that saves all the regs. Basically the '_EN' version
2335 * represents the current state of the function.
2337 * Returns the address of the trampoline that is currently being called
2339 unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec)
2341 struct ftrace_ops *ops;
2343 /* Trampolines take precedence over regs */
2344 if (rec->flags & FTRACE_FL_TRAMP_EN) {
2345 ops = ftrace_find_tramp_ops_curr(rec);
2346 if (FTRACE_WARN_ON(!ops)) {
2347 pr_warn("Bad trampoline accounting at: %p (%pS)\n",
2348 (void *)rec->ip, (void *)rec->ip);
2349 /* Ftrace is shutting down, return anything */
2350 return (unsigned long)FTRACE_ADDR;
2352 return ops->trampoline;
2355 if (rec->flags & FTRACE_FL_REGS_EN)
2356 return (unsigned long)FTRACE_REGS_ADDR;
2357 else
2358 return (unsigned long)FTRACE_ADDR;
2361 static int
2362 __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
2364 unsigned long ftrace_old_addr;
2365 unsigned long ftrace_addr;
2366 int ret;
2368 ftrace_addr = ftrace_get_addr_new(rec);
2370 /* This needs to be done before we call ftrace_update_record */
2371 ftrace_old_addr = ftrace_get_addr_curr(rec);
2373 ret = ftrace_update_record(rec, enable);
2375 ftrace_bug_type = FTRACE_BUG_UNKNOWN;
2377 switch (ret) {
2378 case FTRACE_UPDATE_IGNORE:
2379 return 0;
2381 case FTRACE_UPDATE_MAKE_CALL:
2382 ftrace_bug_type = FTRACE_BUG_CALL;
2383 return ftrace_make_call(rec, ftrace_addr);
2385 case FTRACE_UPDATE_MAKE_NOP:
2386 ftrace_bug_type = FTRACE_BUG_NOP;
2387 return ftrace_make_nop(NULL, rec, ftrace_old_addr);
2389 case FTRACE_UPDATE_MODIFY_CALL:
2390 ftrace_bug_type = FTRACE_BUG_UPDATE;
2391 return ftrace_modify_call(rec, ftrace_old_addr, ftrace_addr);
2394 return -1; /* unknow ftrace bug */
2397 void __weak ftrace_replace_code(int mod_flags)
2399 struct dyn_ftrace *rec;
2400 struct ftrace_page *pg;
2401 int enable = mod_flags & FTRACE_MODIFY_ENABLE_FL;
2402 int schedulable = mod_flags & FTRACE_MODIFY_MAY_SLEEP_FL;
2403 int failed;
2405 if (unlikely(ftrace_disabled))
2406 return;
2408 do_for_each_ftrace_rec(pg, rec) {
2410 if (rec->flags & FTRACE_FL_DISABLED)
2411 continue;
2413 failed = __ftrace_replace_code(rec, enable);
2414 if (failed) {
2415 ftrace_bug(failed, rec);
2416 /* Stop processing */
2417 return;
2419 if (schedulable)
2420 cond_resched();
2421 } while_for_each_ftrace_rec();
2424 struct ftrace_rec_iter {
2425 struct ftrace_page *pg;
2426 int index;
2430 * ftrace_rec_iter_start, start up iterating over traced functions
2432 * Returns an iterator handle that is used to iterate over all
2433 * the records that represent address locations where functions
2434 * are traced.
2436 * May return NULL if no records are available.
2438 struct ftrace_rec_iter *ftrace_rec_iter_start(void)
2441 * We only use a single iterator.
2442 * Protected by the ftrace_lock mutex.
2444 static struct ftrace_rec_iter ftrace_rec_iter;
2445 struct ftrace_rec_iter *iter = &ftrace_rec_iter;
2447 iter->pg = ftrace_pages_start;
2448 iter->index = 0;
2450 /* Could have empty pages */
2451 while (iter->pg && !iter->pg->index)
2452 iter->pg = iter->pg->next;
2454 if (!iter->pg)
2455 return NULL;
2457 return iter;
2461 * ftrace_rec_iter_next, get the next record to process.
2462 * @iter: The handle to the iterator.
2464 * Returns the next iterator after the given iterator @iter.
2466 struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter)
2468 iter->index++;
2470 if (iter->index >= iter->pg->index) {
2471 iter->pg = iter->pg->next;
2472 iter->index = 0;
2474 /* Could have empty pages */
2475 while (iter->pg && !iter->pg->index)
2476 iter->pg = iter->pg->next;
2479 if (!iter->pg)
2480 return NULL;
2482 return iter;
2486 * ftrace_rec_iter_record, get the record at the iterator location
2487 * @iter: The current iterator location
2489 * Returns the record that the current @iter is at.
2491 struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter)
2493 return &iter->pg->records[iter->index];
2496 static int
2497 ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
2499 int ret;
2501 if (unlikely(ftrace_disabled))
2502 return 0;
2504 ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR);
2505 if (ret) {
2506 ftrace_bug_type = FTRACE_BUG_INIT;
2507 ftrace_bug(ret, rec);
2508 return 0;
2510 return 1;
2514 * archs can override this function if they must do something
2515 * before the modifying code is performed.
2517 int __weak ftrace_arch_code_modify_prepare(void)
2519 return 0;
2523 * archs can override this function if they must do something
2524 * after the modifying code is performed.
2526 int __weak ftrace_arch_code_modify_post_process(void)
2528 return 0;
2531 void ftrace_modify_all_code(int command)
2533 int update = command & FTRACE_UPDATE_TRACE_FUNC;
2534 int mod_flags = 0;
2535 int err = 0;
2537 if (command & FTRACE_MAY_SLEEP)
2538 mod_flags = FTRACE_MODIFY_MAY_SLEEP_FL;
2541 * If the ftrace_caller calls a ftrace_ops func directly,
2542 * we need to make sure that it only traces functions it
2543 * expects to trace. When doing the switch of functions,
2544 * we need to update to the ftrace_ops_list_func first
2545 * before the transition between old and new calls are set,
2546 * as the ftrace_ops_list_func will check the ops hashes
2547 * to make sure the ops are having the right functions
2548 * traced.
2550 if (update) {
2551 err = ftrace_update_ftrace_func(ftrace_ops_list_func);
2552 if (FTRACE_WARN_ON(err))
2553 return;
2556 if (command & FTRACE_UPDATE_CALLS)
2557 ftrace_replace_code(mod_flags | FTRACE_MODIFY_ENABLE_FL);
2558 else if (command & FTRACE_DISABLE_CALLS)
2559 ftrace_replace_code(mod_flags);
2561 if (update && ftrace_trace_function != ftrace_ops_list_func) {
2562 function_trace_op = set_function_trace_op;
2563 smp_wmb();
2564 /* If irqs are disabled, we are in stop machine */
2565 if (!irqs_disabled())
2566 smp_call_function(ftrace_sync_ipi, NULL, 1);
2567 err = ftrace_update_ftrace_func(ftrace_trace_function);
2568 if (FTRACE_WARN_ON(err))
2569 return;
2572 if (command & FTRACE_START_FUNC_RET)
2573 err = ftrace_enable_ftrace_graph_caller();
2574 else if (command & FTRACE_STOP_FUNC_RET)
2575 err = ftrace_disable_ftrace_graph_caller();
2576 FTRACE_WARN_ON(err);
2579 static int __ftrace_modify_code(void *data)
2581 int *command = data;
2583 ftrace_modify_all_code(*command);
2585 return 0;
2589 * ftrace_run_stop_machine, go back to the stop machine method
2590 * @command: The command to tell ftrace what to do
2592 * If an arch needs to fall back to the stop machine method, the
2593 * it can call this function.
2595 void ftrace_run_stop_machine(int command)
2597 stop_machine(__ftrace_modify_code, &command, NULL);
2601 * arch_ftrace_update_code, modify the code to trace or not trace
2602 * @command: The command that needs to be done
2604 * Archs can override this function if it does not need to
2605 * run stop_machine() to modify code.
2607 void __weak arch_ftrace_update_code(int command)
2609 ftrace_run_stop_machine(command);
2612 static void ftrace_run_update_code(int command)
2614 int ret;
2616 ret = ftrace_arch_code_modify_prepare();
2617 FTRACE_WARN_ON(ret);
2618 if (ret)
2619 return;
2622 * By default we use stop_machine() to modify the code.
2623 * But archs can do what ever they want as long as it
2624 * is safe. The stop_machine() is the safest, but also
2625 * produces the most overhead.
2627 arch_ftrace_update_code(command);
2629 ret = ftrace_arch_code_modify_post_process();
2630 FTRACE_WARN_ON(ret);
2633 static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
2634 struct ftrace_ops_hash *old_hash)
2636 ops->flags |= FTRACE_OPS_FL_MODIFYING;
2637 ops->old_hash.filter_hash = old_hash->filter_hash;
2638 ops->old_hash.notrace_hash = old_hash->notrace_hash;
2639 ftrace_run_update_code(command);
2640 ops->old_hash.filter_hash = NULL;
2641 ops->old_hash.notrace_hash = NULL;
2642 ops->flags &= ~FTRACE_OPS_FL_MODIFYING;
2645 static ftrace_func_t saved_ftrace_func;
2646 static int ftrace_start_up;
2648 void __weak arch_ftrace_trampoline_free(struct ftrace_ops *ops)
2652 static void ftrace_startup_enable(int command)
2654 if (saved_ftrace_func != ftrace_trace_function) {
2655 saved_ftrace_func = ftrace_trace_function;
2656 command |= FTRACE_UPDATE_TRACE_FUNC;
2659 if (!command || !ftrace_enabled)
2660 return;
2662 ftrace_run_update_code(command);
2665 static void ftrace_startup_all(int command)
2667 update_all_ops = true;
2668 ftrace_startup_enable(command);
2669 update_all_ops = false;
2672 int ftrace_startup(struct ftrace_ops *ops, int command)
2674 int ret;
2676 if (unlikely(ftrace_disabled))
2677 return -ENODEV;
2679 ret = __register_ftrace_function(ops);
2680 if (ret)
2681 return ret;
2683 ftrace_start_up++;
2686 * Note that ftrace probes uses this to start up
2687 * and modify functions it will probe. But we still
2688 * set the ADDING flag for modification, as probes
2689 * do not have trampolines. If they add them in the
2690 * future, then the probes will need to distinguish
2691 * between adding and updating probes.
2693 ops->flags |= FTRACE_OPS_FL_ENABLED | FTRACE_OPS_FL_ADDING;
2695 ret = ftrace_hash_ipmodify_enable(ops);
2696 if (ret < 0) {
2697 /* Rollback registration process */
2698 __unregister_ftrace_function(ops);
2699 ftrace_start_up--;
2700 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2701 return ret;
2704 if (ftrace_hash_rec_enable(ops, 1))
2705 command |= FTRACE_UPDATE_CALLS;
2707 ftrace_startup_enable(command);
2709 ops->flags &= ~FTRACE_OPS_FL_ADDING;
2711 return 0;
2714 int ftrace_shutdown(struct ftrace_ops *ops, int command)
2716 int ret;
2718 if (unlikely(ftrace_disabled))
2719 return -ENODEV;
2721 ret = __unregister_ftrace_function(ops);
2722 if (ret)
2723 return ret;
2725 ftrace_start_up--;
2727 * Just warn in case of unbalance, no need to kill ftrace, it's not
2728 * critical but the ftrace_call callers may be never nopped again after
2729 * further ftrace uses.
2731 WARN_ON_ONCE(ftrace_start_up < 0);
2733 /* Disabling ipmodify never fails */
2734 ftrace_hash_ipmodify_disable(ops);
2736 if (ftrace_hash_rec_disable(ops, 1))
2737 command |= FTRACE_UPDATE_CALLS;
2739 ops->flags &= ~FTRACE_OPS_FL_ENABLED;
2741 if (saved_ftrace_func != ftrace_trace_function) {
2742 saved_ftrace_func = ftrace_trace_function;
2743 command |= FTRACE_UPDATE_TRACE_FUNC;
2746 if (!command || !ftrace_enabled) {
2748 * If these are dynamic or per_cpu ops, they still
2749 * need their data freed. Since, function tracing is
2750 * not currently active, we can just free them
2751 * without synchronizing all CPUs.
2753 if (ops->flags & FTRACE_OPS_FL_DYNAMIC)
2754 goto free_ops;
2756 return 0;
2760 * If the ops uses a trampoline, then it needs to be
2761 * tested first on update.
2763 ops->flags |= FTRACE_OPS_FL_REMOVING;
2764 removed_ops = ops;
2766 /* The trampoline logic checks the old hashes */
2767 ops->old_hash.filter_hash = ops->func_hash->filter_hash;
2768 ops->old_hash.notrace_hash = ops->func_hash->notrace_hash;
2770 ftrace_run_update_code(command);
2773 * If there's no more ops registered with ftrace, run a
2774 * sanity check to make sure all rec flags are cleared.
2776 if (rcu_dereference_protected(ftrace_ops_list,
2777 lockdep_is_held(&ftrace_lock)) == &ftrace_list_end) {
2778 struct ftrace_page *pg;
2779 struct dyn_ftrace *rec;
2781 do_for_each_ftrace_rec(pg, rec) {
2782 if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
2783 pr_warn(" %pS flags:%lx\n",
2784 (void *)rec->ip, rec->flags);
2785 } while_for_each_ftrace_rec();
2788 ops->old_hash.filter_hash = NULL;
2789 ops->old_hash.notrace_hash = NULL;
2791 removed_ops = NULL;
2792 ops->flags &= ~FTRACE_OPS_FL_REMOVING;
2795 * Dynamic ops may be freed, we must make sure that all
2796 * callers are done before leaving this function.
2797 * The same goes for freeing the per_cpu data of the per_cpu
2798 * ops.
2800 if (ops->flags & FTRACE_OPS_FL_DYNAMIC) {
2802 * We need to do a hard force of sched synchronization.
2803 * This is because we use preempt_disable() to do RCU, but
2804 * the function tracers can be called where RCU is not watching
2805 * (like before user_exit()). We can not rely on the RCU
2806 * infrastructure to do the synchronization, thus we must do it
2807 * ourselves.
2809 schedule_on_each_cpu(ftrace_sync);
2812 * When the kernel is preeptive, tasks can be preempted
2813 * while on a ftrace trampoline. Just scheduling a task on
2814 * a CPU is not good enough to flush them. Calling
2815 * synchornize_rcu_tasks() will wait for those tasks to
2816 * execute and either schedule voluntarily or enter user space.
2818 if (IS_ENABLED(CONFIG_PREEMPT))
2819 synchronize_rcu_tasks();
2821 free_ops:
2822 arch_ftrace_trampoline_free(ops);
2825 return 0;
2828 static void ftrace_startup_sysctl(void)
2830 int command;
2832 if (unlikely(ftrace_disabled))
2833 return;
2835 /* Force update next time */
2836 saved_ftrace_func = NULL;
2837 /* ftrace_start_up is true if we want ftrace running */
2838 if (ftrace_start_up) {
2839 command = FTRACE_UPDATE_CALLS;
2840 if (ftrace_graph_active)
2841 command |= FTRACE_START_FUNC_RET;
2842 ftrace_startup_enable(command);
2846 static void ftrace_shutdown_sysctl(void)
2848 int command;
2850 if (unlikely(ftrace_disabled))
2851 return;
2853 /* ftrace_start_up is true if ftrace is running */
2854 if (ftrace_start_up) {
2855 command = FTRACE_DISABLE_CALLS;
2856 if (ftrace_graph_active)
2857 command |= FTRACE_STOP_FUNC_RET;
2858 ftrace_run_update_code(command);
2862 static u64 ftrace_update_time;
2863 unsigned long ftrace_update_tot_cnt;
2865 static inline int ops_traces_mod(struct ftrace_ops *ops)
2868 * Filter_hash being empty will default to trace module.
2869 * But notrace hash requires a test of individual module functions.
2871 return ftrace_hash_empty(ops->func_hash->filter_hash) &&
2872 ftrace_hash_empty(ops->func_hash->notrace_hash);
2876 * Check if the current ops references the record.
2878 * If the ops traces all functions, then it was already accounted for.
2879 * If the ops does not trace the current record function, skip it.
2880 * If the ops ignores the function via notrace filter, skip it.
2882 static inline bool
2883 ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
2885 /* If ops isn't enabled, ignore it */
2886 if (!(ops->flags & FTRACE_OPS_FL_ENABLED))
2887 return false;
2889 /* If ops traces all then it includes this function */
2890 if (ops_traces_mod(ops))
2891 return true;
2893 /* The function must be in the filter */
2894 if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
2895 !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
2896 return false;
2898 /* If in notrace hash, we ignore it too */
2899 if (ftrace_lookup_ip(ops->func_hash->notrace_hash, rec->ip))
2900 return false;
2902 return true;
2905 static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
2907 struct ftrace_page *pg;
2908 struct dyn_ftrace *p;
2909 u64 start, stop;
2910 unsigned long update_cnt = 0;
2911 unsigned long rec_flags = 0;
2912 int i;
2914 start = ftrace_now(raw_smp_processor_id());
2917 * When a module is loaded, this function is called to convert
2918 * the calls to mcount in its text to nops, and also to create
2919 * an entry in the ftrace data. Now, if ftrace is activated
2920 * after this call, but before the module sets its text to
2921 * read-only, the modification of enabling ftrace can fail if
2922 * the read-only is done while ftrace is converting the calls.
2923 * To prevent this, the module's records are set as disabled
2924 * and will be enabled after the call to set the module's text
2925 * to read-only.
2927 if (mod)
2928 rec_flags |= FTRACE_FL_DISABLED;
2930 for (pg = new_pgs; pg; pg = pg->next) {
2932 for (i = 0; i < pg->index; i++) {
2934 /* If something went wrong, bail without enabling anything */
2935 if (unlikely(ftrace_disabled))
2936 return -1;
2938 p = &pg->records[i];
2939 p->flags = rec_flags;
2941 #ifndef CC_USING_NOP_MCOUNT
2943 * Do the initial record conversion from mcount jump
2944 * to the NOP instructions.
2946 if (!ftrace_code_disable(mod, p))
2947 break;
2948 #endif
2950 update_cnt++;
2954 stop = ftrace_now(raw_smp_processor_id());
2955 ftrace_update_time = stop - start;
2956 ftrace_update_tot_cnt += update_cnt;
2958 return 0;
2961 static int ftrace_allocate_records(struct ftrace_page *pg, int count)
2963 int order;
2964 int cnt;
2966 if (WARN_ON(!count))
2967 return -EINVAL;
2969 order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE));
2972 * We want to fill as much as possible. No more than a page
2973 * may be empty.
2975 while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE)
2976 order--;
2978 again:
2979 pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
2981 if (!pg->records) {
2982 /* if we can't allocate this size, try something smaller */
2983 if (!order)
2984 return -ENOMEM;
2985 order >>= 1;
2986 goto again;
2989 cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
2990 pg->size = cnt;
2992 if (cnt > count)
2993 cnt = count;
2995 return cnt;
2998 static struct ftrace_page *
2999 ftrace_allocate_pages(unsigned long num_to_init)
3001 struct ftrace_page *start_pg;
3002 struct ftrace_page *pg;
3003 int order;
3004 int cnt;
3006 if (!num_to_init)
3007 return 0;
3009 start_pg = pg = kzalloc(sizeof(*pg), GFP_KERNEL);
3010 if (!pg)
3011 return NULL;
3014 * Try to allocate as much as possible in one continues
3015 * location that fills in all of the space. We want to
3016 * waste as little space as possible.
3018 for (;;) {
3019 cnt = ftrace_allocate_records(pg, num_to_init);
3020 if (cnt < 0)
3021 goto free_pages;
3023 num_to_init -= cnt;
3024 if (!num_to_init)
3025 break;
3027 pg->next = kzalloc(sizeof(*pg), GFP_KERNEL);
3028 if (!pg->next)
3029 goto free_pages;
3031 pg = pg->next;
3034 return start_pg;
3036 free_pages:
3037 pg = start_pg;
3038 while (pg) {
3039 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
3040 free_pages((unsigned long)pg->records, order);
3041 start_pg = pg->next;
3042 kfree(pg);
3043 pg = start_pg;
3045 pr_info("ftrace: FAILED to allocate memory for functions\n");
3046 return NULL;
3049 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
3051 struct ftrace_iterator {
3052 loff_t pos;
3053 loff_t func_pos;
3054 loff_t mod_pos;
3055 struct ftrace_page *pg;
3056 struct dyn_ftrace *func;
3057 struct ftrace_func_probe *probe;
3058 struct ftrace_func_entry *probe_entry;
3059 struct trace_parser parser;
3060 struct ftrace_hash *hash;
3061 struct ftrace_ops *ops;
3062 struct trace_array *tr;
3063 struct list_head *mod_list;
3064 int pidx;
3065 int idx;
3066 unsigned flags;
3069 static void *
3070 t_probe_next(struct seq_file *m, loff_t *pos)
3072 struct ftrace_iterator *iter = m->private;
3073 struct trace_array *tr = iter->ops->private;
3074 struct list_head *func_probes;
3075 struct ftrace_hash *hash;
3076 struct list_head *next;
3077 struct hlist_node *hnd = NULL;
3078 struct hlist_head *hhd;
3079 int size;
3081 (*pos)++;
3082 iter->pos = *pos;
3084 if (!tr)
3085 return NULL;
3087 func_probes = &tr->func_probes;
3088 if (list_empty(func_probes))
3089 return NULL;
3091 if (!iter->probe) {
3092 next = func_probes->next;
3093 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3096 if (iter->probe_entry)
3097 hnd = &iter->probe_entry->hlist;
3099 hash = iter->probe->ops.func_hash->filter_hash;
3100 size = 1 << hash->size_bits;
3102 retry:
3103 if (iter->pidx >= size) {
3104 if (iter->probe->list.next == func_probes)
3105 return NULL;
3106 next = iter->probe->list.next;
3107 iter->probe = list_entry(next, struct ftrace_func_probe, list);
3108 hash = iter->probe->ops.func_hash->filter_hash;
3109 size = 1 << hash->size_bits;
3110 iter->pidx = 0;
3113 hhd = &hash->buckets[iter->pidx];
3115 if (hlist_empty(hhd)) {
3116 iter->pidx++;
3117 hnd = NULL;
3118 goto retry;
3121 if (!hnd)
3122 hnd = hhd->first;
3123 else {
3124 hnd = hnd->next;
3125 if (!hnd) {
3126 iter->pidx++;
3127 goto retry;
3131 if (WARN_ON_ONCE(!hnd))
3132 return NULL;
3134 iter->probe_entry = hlist_entry(hnd, struct ftrace_func_entry, hlist);
3136 return iter;
3139 static void *t_probe_start(struct seq_file *m, loff_t *pos)
3141 struct ftrace_iterator *iter = m->private;
3142 void *p = NULL;
3143 loff_t l;
3145 if (!(iter->flags & FTRACE_ITER_DO_PROBES))
3146 return NULL;
3148 if (iter->mod_pos > *pos)
3149 return NULL;
3151 iter->probe = NULL;
3152 iter->probe_entry = NULL;
3153 iter->pidx = 0;
3154 for (l = 0; l <= (*pos - iter->mod_pos); ) {
3155 p = t_probe_next(m, &l);
3156 if (!p)
3157 break;
3159 if (!p)
3160 return NULL;
3162 /* Only set this if we have an item */
3163 iter->flags |= FTRACE_ITER_PROBE;
3165 return iter;
3168 static int
3169 t_probe_show(struct seq_file *m, struct ftrace_iterator *iter)
3171 struct ftrace_func_entry *probe_entry;
3172 struct ftrace_probe_ops *probe_ops;
3173 struct ftrace_func_probe *probe;
3175 probe = iter->probe;
3176 probe_entry = iter->probe_entry;
3178 if (WARN_ON_ONCE(!probe || !probe_entry))
3179 return -EIO;
3181 probe_ops = probe->probe_ops;
3183 if (probe_ops->print)
3184 return probe_ops->print(m, probe_entry->ip, probe_ops, probe->data);
3186 seq_printf(m, "%ps:%ps\n", (void *)probe_entry->ip,
3187 (void *)probe_ops->func);
3189 return 0;
3192 static void *
3193 t_mod_next(struct seq_file *m, loff_t *pos)
3195 struct ftrace_iterator *iter = m->private;
3196 struct trace_array *tr = iter->tr;
3198 (*pos)++;
3199 iter->pos = *pos;
3201 iter->mod_list = iter->mod_list->next;
3203 if (iter->mod_list == &tr->mod_trace ||
3204 iter->mod_list == &tr->mod_notrace) {
3205 iter->flags &= ~FTRACE_ITER_MOD;
3206 return NULL;
3209 iter->mod_pos = *pos;
3211 return iter;
3214 static void *t_mod_start(struct seq_file *m, loff_t *pos)
3216 struct ftrace_iterator *iter = m->private;
3217 void *p = NULL;
3218 loff_t l;
3220 if (iter->func_pos > *pos)
3221 return NULL;
3223 iter->mod_pos = iter->func_pos;
3225 /* probes are only available if tr is set */
3226 if (!iter->tr)
3227 return NULL;
3229 for (l = 0; l <= (*pos - iter->func_pos); ) {
3230 p = t_mod_next(m, &l);
3231 if (!p)
3232 break;
3234 if (!p) {
3235 iter->flags &= ~FTRACE_ITER_MOD;
3236 return t_probe_start(m, pos);
3239 /* Only set this if we have an item */
3240 iter->flags |= FTRACE_ITER_MOD;
3242 return iter;
3245 static int
3246 t_mod_show(struct seq_file *m, struct ftrace_iterator *iter)
3248 struct ftrace_mod_load *ftrace_mod;
3249 struct trace_array *tr = iter->tr;
3251 if (WARN_ON_ONCE(!iter->mod_list) ||
3252 iter->mod_list == &tr->mod_trace ||
3253 iter->mod_list == &tr->mod_notrace)
3254 return -EIO;
3256 ftrace_mod = list_entry(iter->mod_list, struct ftrace_mod_load, list);
3258 if (ftrace_mod->func)
3259 seq_printf(m, "%s", ftrace_mod->func);
3260 else
3261 seq_putc(m, '*');
3263 seq_printf(m, ":mod:%s\n", ftrace_mod->module);
3265 return 0;
3268 static void *
3269 t_func_next(struct seq_file *m, loff_t *pos)
3271 struct ftrace_iterator *iter = m->private;
3272 struct dyn_ftrace *rec = NULL;
3274 (*pos)++;
3276 retry:
3277 if (iter->idx >= iter->pg->index) {
3278 if (iter->pg->next) {
3279 iter->pg = iter->pg->next;
3280 iter->idx = 0;
3281 goto retry;
3283 } else {
3284 rec = &iter->pg->records[iter->idx++];
3285 if (((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3286 !ftrace_lookup_ip(iter->hash, rec->ip)) ||
3288 ((iter->flags & FTRACE_ITER_ENABLED) &&
3289 !(rec->flags & FTRACE_FL_ENABLED))) {
3291 rec = NULL;
3292 goto retry;
3296 if (!rec)
3297 return NULL;
3299 iter->pos = iter->func_pos = *pos;
3300 iter->func = rec;
3302 return iter;
3305 static void *
3306 t_next(struct seq_file *m, void *v, loff_t *pos)
3308 struct ftrace_iterator *iter = m->private;
3309 loff_t l = *pos; /* t_probe_start() must use original pos */
3310 void *ret;
3312 if (unlikely(ftrace_disabled))
3313 return NULL;
3315 if (iter->flags & FTRACE_ITER_PROBE)
3316 return t_probe_next(m, pos);
3318 if (iter->flags & FTRACE_ITER_MOD)
3319 return t_mod_next(m, pos);
3321 if (iter->flags & FTRACE_ITER_PRINTALL) {
3322 /* next must increment pos, and t_probe_start does not */
3323 (*pos)++;
3324 return t_mod_start(m, &l);
3327 ret = t_func_next(m, pos);
3329 if (!ret)
3330 return t_mod_start(m, &l);
3332 return ret;
3335 static void reset_iter_read(struct ftrace_iterator *iter)
3337 iter->pos = 0;
3338 iter->func_pos = 0;
3339 iter->flags &= ~(FTRACE_ITER_PRINTALL | FTRACE_ITER_PROBE | FTRACE_ITER_MOD);
3342 static void *t_start(struct seq_file *m, loff_t *pos)
3344 struct ftrace_iterator *iter = m->private;
3345 void *p = NULL;
3346 loff_t l;
3348 mutex_lock(&ftrace_lock);
3350 if (unlikely(ftrace_disabled))
3351 return NULL;
3354 * If an lseek was done, then reset and start from beginning.
3356 if (*pos < iter->pos)
3357 reset_iter_read(iter);
3360 * For set_ftrace_filter reading, if we have the filter
3361 * off, we can short cut and just print out that all
3362 * functions are enabled.
3364 if ((iter->flags & (FTRACE_ITER_FILTER | FTRACE_ITER_NOTRACE)) &&
3365 ftrace_hash_empty(iter->hash)) {
3366 iter->func_pos = 1; /* Account for the message */
3367 if (*pos > 0)
3368 return t_mod_start(m, pos);
3369 iter->flags |= FTRACE_ITER_PRINTALL;
3370 /* reset in case of seek/pread */
3371 iter->flags &= ~FTRACE_ITER_PROBE;
3372 return iter;
3375 if (iter->flags & FTRACE_ITER_MOD)
3376 return t_mod_start(m, pos);
3379 * Unfortunately, we need to restart at ftrace_pages_start
3380 * every time we let go of the ftrace_mutex. This is because
3381 * those pointers can change without the lock.
3383 iter->pg = ftrace_pages_start;
3384 iter->idx = 0;
3385 for (l = 0; l <= *pos; ) {
3386 p = t_func_next(m, &l);
3387 if (!p)
3388 break;
3391 if (!p)
3392 return t_mod_start(m, pos);
3394 return iter;
3397 static void t_stop(struct seq_file *m, void *p)
3399 mutex_unlock(&ftrace_lock);
3402 void * __weak
3403 arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec)
3405 return NULL;
3408 static void add_trampoline_func(struct seq_file *m, struct ftrace_ops *ops,
3409 struct dyn_ftrace *rec)
3411 void *ptr;
3413 ptr = arch_ftrace_trampoline_func(ops, rec);
3414 if (ptr)
3415 seq_printf(m, " ->%pS", ptr);
3418 static int t_show(struct seq_file *m, void *v)
3420 struct ftrace_iterator *iter = m->private;
3421 struct dyn_ftrace *rec;
3423 if (iter->flags & FTRACE_ITER_PROBE)
3424 return t_probe_show(m, iter);
3426 if (iter->flags & FTRACE_ITER_MOD)
3427 return t_mod_show(m, iter);
3429 if (iter->flags & FTRACE_ITER_PRINTALL) {
3430 if (iter->flags & FTRACE_ITER_NOTRACE)
3431 seq_puts(m, "#### no functions disabled ####\n");
3432 else
3433 seq_puts(m, "#### all functions enabled ####\n");
3434 return 0;
3437 rec = iter->func;
3439 if (!rec)
3440 return 0;
3442 seq_printf(m, "%ps", (void *)rec->ip);
3443 if (iter->flags & FTRACE_ITER_ENABLED) {
3444 struct ftrace_ops *ops;
3446 seq_printf(m, " (%ld)%s%s",
3447 ftrace_rec_count(rec),
3448 rec->flags & FTRACE_FL_REGS ? " R" : " ",
3449 rec->flags & FTRACE_FL_IPMODIFY ? " I" : " ");
3450 if (rec->flags & FTRACE_FL_TRAMP_EN) {
3451 ops = ftrace_find_tramp_ops_any(rec);
3452 if (ops) {
3453 do {
3454 seq_printf(m, "\ttramp: %pS (%pS)",
3455 (void *)ops->trampoline,
3456 (void *)ops->func);
3457 add_trampoline_func(m, ops, rec);
3458 ops = ftrace_find_tramp_ops_next(rec, ops);
3459 } while (ops);
3460 } else
3461 seq_puts(m, "\ttramp: ERROR!");
3462 } else {
3463 add_trampoline_func(m, NULL, rec);
3467 seq_putc(m, '\n');
3469 return 0;
3472 static const struct seq_operations show_ftrace_seq_ops = {
3473 .start = t_start,
3474 .next = t_next,
3475 .stop = t_stop,
3476 .show = t_show,
3479 static int
3480 ftrace_avail_open(struct inode *inode, struct file *file)
3482 struct ftrace_iterator *iter;
3484 if (unlikely(ftrace_disabled))
3485 return -ENODEV;
3487 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3488 if (!iter)
3489 return -ENOMEM;
3491 iter->pg = ftrace_pages_start;
3492 iter->ops = &global_ops;
3494 return 0;
3497 static int
3498 ftrace_enabled_open(struct inode *inode, struct file *file)
3500 struct ftrace_iterator *iter;
3502 iter = __seq_open_private(file, &show_ftrace_seq_ops, sizeof(*iter));
3503 if (!iter)
3504 return -ENOMEM;
3506 iter->pg = ftrace_pages_start;
3507 iter->flags = FTRACE_ITER_ENABLED;
3508 iter->ops = &global_ops;
3510 return 0;
3514 * ftrace_regex_open - initialize function tracer filter files
3515 * @ops: The ftrace_ops that hold the hash filters
3516 * @flag: The type of filter to process
3517 * @inode: The inode, usually passed in to your open routine
3518 * @file: The file, usually passed in to your open routine
3520 * ftrace_regex_open() initializes the filter files for the
3521 * @ops. Depending on @flag it may process the filter hash or
3522 * the notrace hash of @ops. With this called from the open
3523 * routine, you can use ftrace_filter_write() for the write
3524 * routine if @flag has FTRACE_ITER_FILTER set, or
3525 * ftrace_notrace_write() if @flag has FTRACE_ITER_NOTRACE set.
3526 * tracing_lseek() should be used as the lseek routine, and
3527 * release must call ftrace_regex_release().
3530 ftrace_regex_open(struct ftrace_ops *ops, int flag,
3531 struct inode *inode, struct file *file)
3533 struct ftrace_iterator *iter;
3534 struct ftrace_hash *hash;
3535 struct list_head *mod_head;
3536 struct trace_array *tr = ops->private;
3537 int ret = 0;
3539 ftrace_ops_init(ops);
3541 if (unlikely(ftrace_disabled))
3542 return -ENODEV;
3544 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
3545 if (!iter)
3546 return -ENOMEM;
3548 if (trace_parser_get_init(&iter->parser, FTRACE_BUFF_MAX)) {
3549 kfree(iter);
3550 return -ENOMEM;
3553 iter->ops = ops;
3554 iter->flags = flag;
3555 iter->tr = tr;
3557 mutex_lock(&ops->func_hash->regex_lock);
3559 if (flag & FTRACE_ITER_NOTRACE) {
3560 hash = ops->func_hash->notrace_hash;
3561 mod_head = tr ? &tr->mod_notrace : NULL;
3562 } else {
3563 hash = ops->func_hash->filter_hash;
3564 mod_head = tr ? &tr->mod_trace : NULL;
3567 iter->mod_list = mod_head;
3569 if (file->f_mode & FMODE_WRITE) {
3570 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
3572 if (file->f_flags & O_TRUNC) {
3573 iter->hash = alloc_ftrace_hash(size_bits);
3574 clear_ftrace_mod_list(mod_head);
3575 } else {
3576 iter->hash = alloc_and_copy_ftrace_hash(size_bits, hash);
3579 if (!iter->hash) {
3580 trace_parser_put(&iter->parser);
3581 kfree(iter);
3582 ret = -ENOMEM;
3583 goto out_unlock;
3585 } else
3586 iter->hash = hash;
3588 if (file->f_mode & FMODE_READ) {
3589 iter->pg = ftrace_pages_start;
3591 ret = seq_open(file, &show_ftrace_seq_ops);
3592 if (!ret) {
3593 struct seq_file *m = file->private_data;
3594 m->private = iter;
3595 } else {
3596 /* Failed */
3597 free_ftrace_hash(iter->hash);
3598 trace_parser_put(&iter->parser);
3599 kfree(iter);
3601 } else
3602 file->private_data = iter;
3604 out_unlock:
3605 mutex_unlock(&ops->func_hash->regex_lock);
3607 return ret;
3610 static int
3611 ftrace_filter_open(struct inode *inode, struct file *file)
3613 struct ftrace_ops *ops = inode->i_private;
3615 return ftrace_regex_open(ops,
3616 FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES,
3617 inode, file);
3620 static int
3621 ftrace_notrace_open(struct inode *inode, struct file *file)
3623 struct ftrace_ops *ops = inode->i_private;
3625 return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE,
3626 inode, file);
3629 /* Type for quick search ftrace basic regexes (globs) from filter_parse_regex */
3630 struct ftrace_glob {
3631 char *search;
3632 unsigned len;
3633 int type;
3637 * If symbols in an architecture don't correspond exactly to the user-visible
3638 * name of what they represent, it is possible to define this function to
3639 * perform the necessary adjustments.
3641 char * __weak arch_ftrace_match_adjust(char *str, const char *search)
3643 return str;
3646 static int ftrace_match(char *str, struct ftrace_glob *g)
3648 int matched = 0;
3649 int slen;
3651 str = arch_ftrace_match_adjust(str, g->search);
3653 switch (g->type) {
3654 case MATCH_FULL:
3655 if (strcmp(str, g->search) == 0)
3656 matched = 1;
3657 break;
3658 case MATCH_FRONT_ONLY:
3659 if (strncmp(str, g->search, g->len) == 0)
3660 matched = 1;
3661 break;
3662 case MATCH_MIDDLE_ONLY:
3663 if (strstr(str, g->search))
3664 matched = 1;
3665 break;
3666 case MATCH_END_ONLY:
3667 slen = strlen(str);
3668 if (slen >= g->len &&
3669 memcmp(str + slen - g->len, g->search, g->len) == 0)
3670 matched = 1;
3671 break;
3672 case MATCH_GLOB:
3673 if (glob_match(g->search, str))
3674 matched = 1;
3675 break;
3678 return matched;
3681 static int
3682 enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
3684 struct ftrace_func_entry *entry;
3685 int ret = 0;
3687 entry = ftrace_lookup_ip(hash, rec->ip);
3688 if (clear_filter) {
3689 /* Do nothing if it doesn't exist */
3690 if (!entry)
3691 return 0;
3693 free_hash_entry(hash, entry);
3694 } else {
3695 /* Do nothing if it exists */
3696 if (entry)
3697 return 0;
3699 ret = add_hash_entry(hash, rec->ip);
3701 return ret;
3704 static int
3705 add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
3706 int clear_filter)
3708 long index = simple_strtoul(func_g->search, NULL, 0);
3709 struct ftrace_page *pg;
3710 struct dyn_ftrace *rec;
3712 /* The index starts at 1 */
3713 if (--index < 0)
3714 return 0;
3716 do_for_each_ftrace_rec(pg, rec) {
3717 if (pg->index <= index) {
3718 index -= pg->index;
3719 /* this is a double loop, break goes to the next page */
3720 break;
3722 rec = &pg->records[index];
3723 enter_record(hash, rec, clear_filter);
3724 return 1;
3725 } while_for_each_ftrace_rec();
3726 return 0;
3729 static int
3730 ftrace_match_record(struct dyn_ftrace *rec, struct ftrace_glob *func_g,
3731 struct ftrace_glob *mod_g, int exclude_mod)
3733 char str[KSYM_SYMBOL_LEN];
3734 char *modname;
3736 kallsyms_lookup(rec->ip, NULL, NULL, &modname, str);
3738 if (mod_g) {
3739 int mod_matches = (modname) ? ftrace_match(modname, mod_g) : 0;
3741 /* blank module name to match all modules */
3742 if (!mod_g->len) {
3743 /* blank module globbing: modname xor exclude_mod */
3744 if (!exclude_mod != !modname)
3745 goto func_match;
3746 return 0;
3750 * exclude_mod is set to trace everything but the given
3751 * module. If it is set and the module matches, then
3752 * return 0. If it is not set, and the module doesn't match
3753 * also return 0. Otherwise, check the function to see if
3754 * that matches.
3756 if (!mod_matches == !exclude_mod)
3757 return 0;
3758 func_match:
3759 /* blank search means to match all funcs in the mod */
3760 if (!func_g->len)
3761 return 1;
3764 return ftrace_match(str, func_g);
3767 static int
3768 match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
3770 struct ftrace_page *pg;
3771 struct dyn_ftrace *rec;
3772 struct ftrace_glob func_g = { .type = MATCH_FULL };
3773 struct ftrace_glob mod_g = { .type = MATCH_FULL };
3774 struct ftrace_glob *mod_match = (mod) ? &mod_g : NULL;
3775 int exclude_mod = 0;
3776 int found = 0;
3777 int ret;
3778 int clear_filter = 0;
3780 if (func) {
3781 func_g.type = filter_parse_regex(func, len, &func_g.search,
3782 &clear_filter);
3783 func_g.len = strlen(func_g.search);
3786 if (mod) {
3787 mod_g.type = filter_parse_regex(mod, strlen(mod),
3788 &mod_g.search, &exclude_mod);
3789 mod_g.len = strlen(mod_g.search);
3792 mutex_lock(&ftrace_lock);
3794 if (unlikely(ftrace_disabled))
3795 goto out_unlock;
3797 if (func_g.type == MATCH_INDEX) {
3798 found = add_rec_by_index(hash, &func_g, clear_filter);
3799 goto out_unlock;
3802 do_for_each_ftrace_rec(pg, rec) {
3804 if (rec->flags & FTRACE_FL_DISABLED)
3805 continue;
3807 if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
3808 ret = enter_record(hash, rec, clear_filter);
3809 if (ret < 0) {
3810 found = ret;
3811 goto out_unlock;
3813 found = 1;
3815 } while_for_each_ftrace_rec();
3816 out_unlock:
3817 mutex_unlock(&ftrace_lock);
3819 return found;
3822 static int
3823 ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
3825 return match_records(hash, buff, len, NULL);
3828 static void ftrace_ops_update_code(struct ftrace_ops *ops,
3829 struct ftrace_ops_hash *old_hash)
3831 struct ftrace_ops *op;
3833 if (!ftrace_enabled)
3834 return;
3836 if (ops->flags & FTRACE_OPS_FL_ENABLED) {
3837 ftrace_run_modify_code(ops, FTRACE_UPDATE_CALLS, old_hash);
3838 return;
3842 * If this is the shared global_ops filter, then we need to
3843 * check if there is another ops that shares it, is enabled.
3844 * If so, we still need to run the modify code.
3846 if (ops->func_hash != &global_ops.local_hash)
3847 return;
3849 do_for_each_ftrace_op(op, ftrace_ops_list) {
3850 if (op->func_hash == &global_ops.local_hash &&
3851 op->flags & FTRACE_OPS_FL_ENABLED) {
3852 ftrace_run_modify_code(op, FTRACE_UPDATE_CALLS, old_hash);
3853 /* Only need to do this once */
3854 return;
3856 } while_for_each_ftrace_op(op);
3859 static int ftrace_hash_move_and_update_ops(struct ftrace_ops *ops,
3860 struct ftrace_hash **orig_hash,
3861 struct ftrace_hash *hash,
3862 int enable)
3864 struct ftrace_ops_hash old_hash_ops;
3865 struct ftrace_hash *old_hash;
3866 int ret;
3868 old_hash = *orig_hash;
3869 old_hash_ops.filter_hash = ops->func_hash->filter_hash;
3870 old_hash_ops.notrace_hash = ops->func_hash->notrace_hash;
3871 ret = ftrace_hash_move(ops, enable, orig_hash, hash);
3872 if (!ret) {
3873 ftrace_ops_update_code(ops, &old_hash_ops);
3874 free_ftrace_hash_rcu(old_hash);
3876 return ret;
3879 static bool module_exists(const char *module)
3881 /* All modules have the symbol __this_module */
3882 const char this_mod[] = "__this_module";
3883 char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2];
3884 unsigned long val;
3885 int n;
3887 n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod);
3889 if (n > sizeof(modname) - 1)
3890 return false;
3892 val = module_kallsyms_lookup_name(modname);
3893 return val != 0;
3896 static int cache_mod(struct trace_array *tr,
3897 const char *func, char *module, int enable)
3899 struct ftrace_mod_load *ftrace_mod, *n;
3900 struct list_head *head = enable ? &tr->mod_trace : &tr->mod_notrace;
3901 int ret;
3903 mutex_lock(&ftrace_lock);
3905 /* We do not cache inverse filters */
3906 if (func[0] == '!') {
3907 func++;
3908 ret = -EINVAL;
3910 /* Look to remove this hash */
3911 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3912 if (strcmp(ftrace_mod->module, module) != 0)
3913 continue;
3915 /* no func matches all */
3916 if (strcmp(func, "*") == 0 ||
3917 (ftrace_mod->func &&
3918 strcmp(ftrace_mod->func, func) == 0)) {
3919 ret = 0;
3920 free_ftrace_mod(ftrace_mod);
3921 continue;
3924 goto out;
3927 ret = -EINVAL;
3928 /* We only care about modules that have not been loaded yet */
3929 if (module_exists(module))
3930 goto out;
3932 /* Save this string off, and execute it when the module is loaded */
3933 ret = ftrace_add_mod(tr, func, module, enable);
3934 out:
3935 mutex_unlock(&ftrace_lock);
3937 return ret;
3940 static int
3941 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
3942 int reset, int enable);
3944 #ifdef CONFIG_MODULES
3945 static void process_mod_list(struct list_head *head, struct ftrace_ops *ops,
3946 char *mod, bool enable)
3948 struct ftrace_mod_load *ftrace_mod, *n;
3949 struct ftrace_hash **orig_hash, *new_hash;
3950 LIST_HEAD(process_mods);
3951 char *func;
3952 int ret;
3954 mutex_lock(&ops->func_hash->regex_lock);
3956 if (enable)
3957 orig_hash = &ops->func_hash->filter_hash;
3958 else
3959 orig_hash = &ops->func_hash->notrace_hash;
3961 new_hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS,
3962 *orig_hash);
3963 if (!new_hash)
3964 goto out; /* warn? */
3966 mutex_lock(&ftrace_lock);
3968 list_for_each_entry_safe(ftrace_mod, n, head, list) {
3970 if (strcmp(ftrace_mod->module, mod) != 0)
3971 continue;
3973 if (ftrace_mod->func)
3974 func = kstrdup(ftrace_mod->func, GFP_KERNEL);
3975 else
3976 func = kstrdup("*", GFP_KERNEL);
3978 if (!func) /* warn? */
3979 continue;
3981 list_del(&ftrace_mod->list);
3982 list_add(&ftrace_mod->list, &process_mods);
3984 /* Use the newly allocated func, as it may be "*" */
3985 kfree(ftrace_mod->func);
3986 ftrace_mod->func = func;
3989 mutex_unlock(&ftrace_lock);
3991 list_for_each_entry_safe(ftrace_mod, n, &process_mods, list) {
3993 func = ftrace_mod->func;
3995 /* Grabs ftrace_lock, which is why we have this extra step */
3996 match_records(new_hash, func, strlen(func), mod);
3997 free_ftrace_mod(ftrace_mod);
4000 if (enable && list_empty(head))
4001 new_hash->flags &= ~FTRACE_HASH_FL_MOD;
4003 mutex_lock(&ftrace_lock);
4005 ret = ftrace_hash_move_and_update_ops(ops, orig_hash,
4006 new_hash, enable);
4007 mutex_unlock(&ftrace_lock);
4009 out:
4010 mutex_unlock(&ops->func_hash->regex_lock);
4012 free_ftrace_hash(new_hash);
4015 static void process_cached_mods(const char *mod_name)
4017 struct trace_array *tr;
4018 char *mod;
4020 mod = kstrdup(mod_name, GFP_KERNEL);
4021 if (!mod)
4022 return;
4024 mutex_lock(&trace_types_lock);
4025 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
4026 if (!list_empty(&tr->mod_trace))
4027 process_mod_list(&tr->mod_trace, tr->ops, mod, true);
4028 if (!list_empty(&tr->mod_notrace))
4029 process_mod_list(&tr->mod_notrace, tr->ops, mod, false);
4031 mutex_unlock(&trace_types_lock);
4033 kfree(mod);
4035 #endif
4038 * We register the module command as a template to show others how
4039 * to register the a command as well.
4042 static int
4043 ftrace_mod_callback(struct trace_array *tr, struct ftrace_hash *hash,
4044 char *func_orig, char *cmd, char *module, int enable)
4046 char *func;
4047 int ret;
4049 /* match_records() modifies func, and we need the original */
4050 func = kstrdup(func_orig, GFP_KERNEL);
4051 if (!func)
4052 return -ENOMEM;
4055 * cmd == 'mod' because we only registered this func
4056 * for the 'mod' ftrace_func_command.
4057 * But if you register one func with multiple commands,
4058 * you can tell which command was used by the cmd
4059 * parameter.
4061 ret = match_records(hash, func, strlen(func), module);
4062 kfree(func);
4064 if (!ret)
4065 return cache_mod(tr, func_orig, module, enable);
4066 if (ret < 0)
4067 return ret;
4068 return 0;
4071 static struct ftrace_func_command ftrace_mod_cmd = {
4072 .name = "mod",
4073 .func = ftrace_mod_callback,
4076 static int __init ftrace_mod_cmd_init(void)
4078 return register_ftrace_command(&ftrace_mod_cmd);
4080 core_initcall(ftrace_mod_cmd_init);
4082 static void function_trace_probe_call(unsigned long ip, unsigned long parent_ip,
4083 struct ftrace_ops *op, struct pt_regs *pt_regs)
4085 struct ftrace_probe_ops *probe_ops;
4086 struct ftrace_func_probe *probe;
4088 probe = container_of(op, struct ftrace_func_probe, ops);
4089 probe_ops = probe->probe_ops;
4092 * Disable preemption for these calls to prevent a RCU grace
4093 * period. This syncs the hash iteration and freeing of items
4094 * on the hash. rcu_read_lock is too dangerous here.
4096 preempt_disable_notrace();
4097 probe_ops->func(ip, parent_ip, probe->tr, probe_ops, probe->data);
4098 preempt_enable_notrace();
4101 struct ftrace_func_map {
4102 struct ftrace_func_entry entry;
4103 void *data;
4106 struct ftrace_func_mapper {
4107 struct ftrace_hash hash;
4111 * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
4113 * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
4115 struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
4117 struct ftrace_hash *hash;
4120 * The mapper is simply a ftrace_hash, but since the entries
4121 * in the hash are not ftrace_func_entry type, we define it
4122 * as a separate structure.
4124 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4125 return (struct ftrace_func_mapper *)hash;
4129 * ftrace_func_mapper_find_ip - Find some data mapped to an ip
4130 * @mapper: The mapper that has the ip maps
4131 * @ip: the instruction pointer to find the data for
4133 * Returns the data mapped to @ip if found otherwise NULL. The return
4134 * is actually the address of the mapper data pointer. The address is
4135 * returned for use cases where the data is no bigger than a long, and
4136 * the user can use the data pointer as its data instead of having to
4137 * allocate more memory for the reference.
4139 void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
4140 unsigned long ip)
4142 struct ftrace_func_entry *entry;
4143 struct ftrace_func_map *map;
4145 entry = ftrace_lookup_ip(&mapper->hash, ip);
4146 if (!entry)
4147 return NULL;
4149 map = (struct ftrace_func_map *)entry;
4150 return &map->data;
4154 * ftrace_func_mapper_add_ip - Map some data to an ip
4155 * @mapper: The mapper that has the ip maps
4156 * @ip: The instruction pointer address to map @data to
4157 * @data: The data to map to @ip
4159 * Returns 0 on succes otherwise an error.
4161 int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
4162 unsigned long ip, void *data)
4164 struct ftrace_func_entry *entry;
4165 struct ftrace_func_map *map;
4167 entry = ftrace_lookup_ip(&mapper->hash, ip);
4168 if (entry)
4169 return -EBUSY;
4171 map = kmalloc(sizeof(*map), GFP_KERNEL);
4172 if (!map)
4173 return -ENOMEM;
4175 map->entry.ip = ip;
4176 map->data = data;
4178 __add_hash_entry(&mapper->hash, &map->entry);
4180 return 0;
4184 * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
4185 * @mapper: The mapper that has the ip maps
4186 * @ip: The instruction pointer address to remove the data from
4188 * Returns the data if it is found, otherwise NULL.
4189 * Note, if the data pointer is used as the data itself, (see
4190 * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
4191 * if the data pointer was set to zero.
4193 void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
4194 unsigned long ip)
4196 struct ftrace_func_entry *entry;
4197 struct ftrace_func_map *map;
4198 void *data;
4200 entry = ftrace_lookup_ip(&mapper->hash, ip);
4201 if (!entry)
4202 return NULL;
4204 map = (struct ftrace_func_map *)entry;
4205 data = map->data;
4207 remove_hash_entry(&mapper->hash, entry);
4208 kfree(entry);
4210 return data;
4214 * free_ftrace_func_mapper - free a mapping of ips and data
4215 * @mapper: The mapper that has the ip maps
4216 * @free_func: A function to be called on each data item.
4218 * This is used to free the function mapper. The @free_func is optional
4219 * and can be used if the data needs to be freed as well.
4221 void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
4222 ftrace_mapper_func free_func)
4224 struct ftrace_func_entry *entry;
4225 struct ftrace_func_map *map;
4226 struct hlist_head *hhd;
4227 int size = 1 << mapper->hash.size_bits;
4228 int i;
4230 if (free_func && mapper->hash.count) {
4231 for (i = 0; i < size; i++) {
4232 hhd = &mapper->hash.buckets[i];
4233 hlist_for_each_entry(entry, hhd, hlist) {
4234 map = (struct ftrace_func_map *)entry;
4235 free_func(map);
4239 free_ftrace_hash(&mapper->hash);
4242 static void release_probe(struct ftrace_func_probe *probe)
4244 struct ftrace_probe_ops *probe_ops;
4246 mutex_lock(&ftrace_lock);
4248 WARN_ON(probe->ref <= 0);
4250 /* Subtract the ref that was used to protect this instance */
4251 probe->ref--;
4253 if (!probe->ref) {
4254 probe_ops = probe->probe_ops;
4256 * Sending zero as ip tells probe_ops to free
4257 * the probe->data itself
4259 if (probe_ops->free)
4260 probe_ops->free(probe_ops, probe->tr, 0, probe->data);
4261 list_del(&probe->list);
4262 kfree(probe);
4264 mutex_unlock(&ftrace_lock);
4267 static void acquire_probe_locked(struct ftrace_func_probe *probe)
4270 * Add one ref to keep it from being freed when releasing the
4271 * ftrace_lock mutex.
4273 probe->ref++;
4277 register_ftrace_function_probe(char *glob, struct trace_array *tr,
4278 struct ftrace_probe_ops *probe_ops,
4279 void *data)
4281 struct ftrace_func_entry *entry;
4282 struct ftrace_func_probe *probe;
4283 struct ftrace_hash **orig_hash;
4284 struct ftrace_hash *old_hash;
4285 struct ftrace_hash *hash;
4286 int count = 0;
4287 int size;
4288 int ret;
4289 int i;
4291 if (WARN_ON(!tr))
4292 return -EINVAL;
4294 /* We do not support '!' for function probes */
4295 if (WARN_ON(glob[0] == '!'))
4296 return -EINVAL;
4299 mutex_lock(&ftrace_lock);
4300 /* Check if the probe_ops is already registered */
4301 list_for_each_entry(probe, &tr->func_probes, list) {
4302 if (probe->probe_ops == probe_ops)
4303 break;
4305 if (&probe->list == &tr->func_probes) {
4306 probe = kzalloc(sizeof(*probe), GFP_KERNEL);
4307 if (!probe) {
4308 mutex_unlock(&ftrace_lock);
4309 return -ENOMEM;
4311 probe->probe_ops = probe_ops;
4312 probe->ops.func = function_trace_probe_call;
4313 probe->tr = tr;
4314 ftrace_ops_init(&probe->ops);
4315 list_add(&probe->list, &tr->func_probes);
4318 acquire_probe_locked(probe);
4320 mutex_unlock(&ftrace_lock);
4322 mutex_lock(&probe->ops.func_hash->regex_lock);
4324 orig_hash = &probe->ops.func_hash->filter_hash;
4325 old_hash = *orig_hash;
4326 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4328 ret = ftrace_match_records(hash, glob, strlen(glob));
4330 /* Nothing found? */
4331 if (!ret)
4332 ret = -EINVAL;
4334 if (ret < 0)
4335 goto out;
4337 size = 1 << hash->size_bits;
4338 for (i = 0; i < size; i++) {
4339 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4340 if (ftrace_lookup_ip(old_hash, entry->ip))
4341 continue;
4343 * The caller might want to do something special
4344 * for each function we find. We call the callback
4345 * to give the caller an opportunity to do so.
4347 if (probe_ops->init) {
4348 ret = probe_ops->init(probe_ops, tr,
4349 entry->ip, data,
4350 &probe->data);
4351 if (ret < 0) {
4352 if (probe_ops->free && count)
4353 probe_ops->free(probe_ops, tr,
4354 0, probe->data);
4355 probe->data = NULL;
4356 goto out;
4359 count++;
4363 mutex_lock(&ftrace_lock);
4365 if (!count) {
4366 /* Nothing was added? */
4367 ret = -EINVAL;
4368 goto out_unlock;
4371 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4372 hash, 1);
4373 if (ret < 0)
4374 goto err_unlock;
4376 /* One ref for each new function traced */
4377 probe->ref += count;
4379 if (!(probe->ops.flags & FTRACE_OPS_FL_ENABLED))
4380 ret = ftrace_startup(&probe->ops, 0);
4382 out_unlock:
4383 mutex_unlock(&ftrace_lock);
4385 if (!ret)
4386 ret = count;
4387 out:
4388 mutex_unlock(&probe->ops.func_hash->regex_lock);
4389 free_ftrace_hash(hash);
4391 release_probe(probe);
4393 return ret;
4395 err_unlock:
4396 if (!probe_ops->free || !count)
4397 goto out_unlock;
4399 /* Failed to do the move, need to call the free functions */
4400 for (i = 0; i < size; i++) {
4401 hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
4402 if (ftrace_lookup_ip(old_hash, entry->ip))
4403 continue;
4404 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4407 goto out_unlock;
4411 unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
4412 struct ftrace_probe_ops *probe_ops)
4414 struct ftrace_ops_hash old_hash_ops;
4415 struct ftrace_func_entry *entry;
4416 struct ftrace_func_probe *probe;
4417 struct ftrace_glob func_g;
4418 struct ftrace_hash **orig_hash;
4419 struct ftrace_hash *old_hash;
4420 struct ftrace_hash *hash = NULL;
4421 struct hlist_node *tmp;
4422 struct hlist_head hhd;
4423 char str[KSYM_SYMBOL_LEN];
4424 int count = 0;
4425 int i, ret = -ENODEV;
4426 int size;
4428 if (!glob || !strlen(glob) || !strcmp(glob, "*"))
4429 func_g.search = NULL;
4430 else {
4431 int not;
4433 func_g.type = filter_parse_regex(glob, strlen(glob),
4434 &func_g.search, &not);
4435 func_g.len = strlen(func_g.search);
4437 /* we do not support '!' for function probes */
4438 if (WARN_ON(not))
4439 return -EINVAL;
4442 mutex_lock(&ftrace_lock);
4443 /* Check if the probe_ops is already registered */
4444 list_for_each_entry(probe, &tr->func_probes, list) {
4445 if (probe->probe_ops == probe_ops)
4446 break;
4448 if (&probe->list == &tr->func_probes)
4449 goto err_unlock_ftrace;
4451 ret = -EINVAL;
4452 if (!(probe->ops.flags & FTRACE_OPS_FL_INITIALIZED))
4453 goto err_unlock_ftrace;
4455 acquire_probe_locked(probe);
4457 mutex_unlock(&ftrace_lock);
4459 mutex_lock(&probe->ops.func_hash->regex_lock);
4461 orig_hash = &probe->ops.func_hash->filter_hash;
4462 old_hash = *orig_hash;
4464 if (ftrace_hash_empty(old_hash))
4465 goto out_unlock;
4467 old_hash_ops.filter_hash = old_hash;
4468 /* Probes only have filters */
4469 old_hash_ops.notrace_hash = NULL;
4471 ret = -ENOMEM;
4472 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);
4473 if (!hash)
4474 goto out_unlock;
4476 INIT_HLIST_HEAD(&hhd);
4478 size = 1 << hash->size_bits;
4479 for (i = 0; i < size; i++) {
4480 hlist_for_each_entry_safe(entry, tmp, &hash->buckets[i], hlist) {
4482 if (func_g.search) {
4483 kallsyms_lookup(entry->ip, NULL, NULL,
4484 NULL, str);
4485 if (!ftrace_match(str, &func_g))
4486 continue;
4488 count++;
4489 remove_hash_entry(hash, entry);
4490 hlist_add_head(&entry->hlist, &hhd);
4494 /* Nothing found? */
4495 if (!count) {
4496 ret = -EINVAL;
4497 goto out_unlock;
4500 mutex_lock(&ftrace_lock);
4502 WARN_ON(probe->ref < count);
4504 probe->ref -= count;
4506 if (ftrace_hash_empty(hash))
4507 ftrace_shutdown(&probe->ops, 0);
4509 ret = ftrace_hash_move_and_update_ops(&probe->ops, orig_hash,
4510 hash, 1);
4512 /* still need to update the function call sites */
4513 if (ftrace_enabled && !ftrace_hash_empty(hash))
4514 ftrace_run_modify_code(&probe->ops, FTRACE_UPDATE_CALLS,
4515 &old_hash_ops);
4516 synchronize_rcu();
4518 hlist_for_each_entry_safe(entry, tmp, &hhd, hlist) {
4519 hlist_del(&entry->hlist);
4520 if (probe_ops->free)
4521 probe_ops->free(probe_ops, tr, entry->ip, probe->data);
4522 kfree(entry);
4524 mutex_unlock(&ftrace_lock);
4526 out_unlock:
4527 mutex_unlock(&probe->ops.func_hash->regex_lock);
4528 free_ftrace_hash(hash);
4530 release_probe(probe);
4532 return ret;
4534 err_unlock_ftrace:
4535 mutex_unlock(&ftrace_lock);
4536 return ret;
4539 void clear_ftrace_function_probes(struct trace_array *tr)
4541 struct ftrace_func_probe *probe, *n;
4543 list_for_each_entry_safe(probe, n, &tr->func_probes, list)
4544 unregister_ftrace_function_probe_func(NULL, tr, probe->probe_ops);
4547 static LIST_HEAD(ftrace_commands);
4548 static DEFINE_MUTEX(ftrace_cmd_mutex);
4551 * Currently we only register ftrace commands from __init, so mark this
4552 * __init too.
4554 __init int register_ftrace_command(struct ftrace_func_command *cmd)
4556 struct ftrace_func_command *p;
4557 int ret = 0;
4559 mutex_lock(&ftrace_cmd_mutex);
4560 list_for_each_entry(p, &ftrace_commands, list) {
4561 if (strcmp(cmd->name, p->name) == 0) {
4562 ret = -EBUSY;
4563 goto out_unlock;
4566 list_add(&cmd->list, &ftrace_commands);
4567 out_unlock:
4568 mutex_unlock(&ftrace_cmd_mutex);
4570 return ret;
4574 * Currently we only unregister ftrace commands from __init, so mark
4575 * this __init too.
4577 __init int unregister_ftrace_command(struct ftrace_func_command *cmd)
4579 struct ftrace_func_command *p, *n;
4580 int ret = -ENODEV;
4582 mutex_lock(&ftrace_cmd_mutex);
4583 list_for_each_entry_safe(p, n, &ftrace_commands, list) {
4584 if (strcmp(cmd->name, p->name) == 0) {
4585 ret = 0;
4586 list_del_init(&p->list);
4587 goto out_unlock;
4590 out_unlock:
4591 mutex_unlock(&ftrace_cmd_mutex);
4593 return ret;
4596 static int ftrace_process_regex(struct ftrace_iterator *iter,
4597 char *buff, int len, int enable)
4599 struct ftrace_hash *hash = iter->hash;
4600 struct trace_array *tr = iter->ops->private;
4601 char *func, *command, *next = buff;
4602 struct ftrace_func_command *p;
4603 int ret = -EINVAL;
4605 func = strsep(&next, ":");
4607 if (!next) {
4608 ret = ftrace_match_records(hash, func, len);
4609 if (!ret)
4610 ret = -EINVAL;
4611 if (ret < 0)
4612 return ret;
4613 return 0;
4616 /* command found */
4618 command = strsep(&next, ":");
4620 mutex_lock(&ftrace_cmd_mutex);
4621 list_for_each_entry(p, &ftrace_commands, list) {
4622 if (strcmp(p->name, command) == 0) {
4623 ret = p->func(tr, hash, func, command, next, enable);
4624 goto out_unlock;
4627 out_unlock:
4628 mutex_unlock(&ftrace_cmd_mutex);
4630 return ret;
4633 static ssize_t
4634 ftrace_regex_write(struct file *file, const char __user *ubuf,
4635 size_t cnt, loff_t *ppos, int enable)
4637 struct ftrace_iterator *iter;
4638 struct trace_parser *parser;
4639 ssize_t ret, read;
4641 if (!cnt)
4642 return 0;
4644 if (file->f_mode & FMODE_READ) {
4645 struct seq_file *m = file->private_data;
4646 iter = m->private;
4647 } else
4648 iter = file->private_data;
4650 if (unlikely(ftrace_disabled))
4651 return -ENODEV;
4653 /* iter->hash is a local copy, so we don't need regex_lock */
4655 parser = &iter->parser;
4656 read = trace_get_user(parser, ubuf, cnt, ppos);
4658 if (read >= 0 && trace_parser_loaded(parser) &&
4659 !trace_parser_cont(parser)) {
4660 ret = ftrace_process_regex(iter, parser->buffer,
4661 parser->idx, enable);
4662 trace_parser_clear(parser);
4663 if (ret < 0)
4664 goto out;
4667 ret = read;
4668 out:
4669 return ret;
4672 ssize_t
4673 ftrace_filter_write(struct file *file, const char __user *ubuf,
4674 size_t cnt, loff_t *ppos)
4676 return ftrace_regex_write(file, ubuf, cnt, ppos, 1);
4679 ssize_t
4680 ftrace_notrace_write(struct file *file, const char __user *ubuf,
4681 size_t cnt, loff_t *ppos)
4683 return ftrace_regex_write(file, ubuf, cnt, ppos, 0);
4686 static int
4687 ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)
4689 struct ftrace_func_entry *entry;
4691 if (!ftrace_location(ip))
4692 return -EINVAL;
4694 if (remove) {
4695 entry = ftrace_lookup_ip(hash, ip);
4696 if (!entry)
4697 return -ENOENT;
4698 free_hash_entry(hash, entry);
4699 return 0;
4702 return add_hash_entry(hash, ip);
4705 static int
4706 ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,
4707 unsigned long ip, int remove, int reset, int enable)
4709 struct ftrace_hash **orig_hash;
4710 struct ftrace_hash *hash;
4711 int ret;
4713 if (unlikely(ftrace_disabled))
4714 return -ENODEV;
4716 mutex_lock(&ops->func_hash->regex_lock);
4718 if (enable)
4719 orig_hash = &ops->func_hash->filter_hash;
4720 else
4721 orig_hash = &ops->func_hash->notrace_hash;
4723 if (reset)
4724 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4725 else
4726 hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, *orig_hash);
4728 if (!hash) {
4729 ret = -ENOMEM;
4730 goto out_regex_unlock;
4733 if (buf && !ftrace_match_records(hash, buf, len)) {
4734 ret = -EINVAL;
4735 goto out_regex_unlock;
4737 if (ip) {
4738 ret = ftrace_match_addr(hash, ip, remove);
4739 if (ret < 0)
4740 goto out_regex_unlock;
4743 mutex_lock(&ftrace_lock);
4744 ret = ftrace_hash_move_and_update_ops(ops, orig_hash, hash, enable);
4745 mutex_unlock(&ftrace_lock);
4747 out_regex_unlock:
4748 mutex_unlock(&ops->func_hash->regex_lock);
4750 free_ftrace_hash(hash);
4751 return ret;
4754 static int
4755 ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,
4756 int reset, int enable)
4758 return ftrace_set_hash(ops, 0, 0, ip, remove, reset, enable);
4762 * ftrace_set_filter_ip - set a function to filter on in ftrace by address
4763 * @ops - the ops to set the filter with
4764 * @ip - the address to add to or remove from the filter.
4765 * @remove - non zero to remove the ip from the filter
4766 * @reset - non zero to reset all filters before applying this filter.
4768 * Filters denote which functions should be enabled when tracing is enabled
4769 * If @ip is NULL, it failes to update filter.
4771 int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
4772 int remove, int reset)
4774 ftrace_ops_init(ops);
4775 return ftrace_set_addr(ops, ip, remove, reset, 1);
4777 EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);
4780 * ftrace_ops_set_global_filter - setup ops to use global filters
4781 * @ops - the ops which will use the global filters
4783 * ftrace users who need global function trace filtering should call this.
4784 * It can set the global filter only if ops were not initialized before.
4786 void ftrace_ops_set_global_filter(struct ftrace_ops *ops)
4788 if (ops->flags & FTRACE_OPS_FL_INITIALIZED)
4789 return;
4791 ftrace_ops_init(ops);
4792 ops->func_hash = &global_ops.local_hash;
4794 EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);
4796 static int
4797 ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,
4798 int reset, int enable)
4800 return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);
4804 * ftrace_set_filter - set a function to filter on in ftrace
4805 * @ops - the ops to set the filter with
4806 * @buf - the string that holds the function filter text.
4807 * @len - the length of the string.
4808 * @reset - non zero to reset all filters before applying this filter.
4810 * Filters denote which functions should be enabled when tracing is enabled.
4811 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4813 int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
4814 int len, int reset)
4816 ftrace_ops_init(ops);
4817 return ftrace_set_regex(ops, buf, len, reset, 1);
4819 EXPORT_SYMBOL_GPL(ftrace_set_filter);
4822 * ftrace_set_notrace - set a function to not trace in ftrace
4823 * @ops - the ops to set the notrace filter with
4824 * @buf - the string that holds the function notrace text.
4825 * @len - the length of the string.
4826 * @reset - non zero to reset all filters before applying this filter.
4828 * Notrace Filters denote which functions should not be enabled when tracing
4829 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4830 * for tracing.
4832 int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
4833 int len, int reset)
4835 ftrace_ops_init(ops);
4836 return ftrace_set_regex(ops, buf, len, reset, 0);
4838 EXPORT_SYMBOL_GPL(ftrace_set_notrace);
4840 * ftrace_set_global_filter - set a function to filter on with global tracers
4841 * @buf - the string that holds the function filter text.
4842 * @len - the length of the string.
4843 * @reset - non zero to reset all filters before applying this filter.
4845 * Filters denote which functions should be enabled when tracing is enabled.
4846 * If @buf is NULL and reset is set, all functions will be enabled for tracing.
4848 void ftrace_set_global_filter(unsigned char *buf, int len, int reset)
4850 ftrace_set_regex(&global_ops, buf, len, reset, 1);
4852 EXPORT_SYMBOL_GPL(ftrace_set_global_filter);
4855 * ftrace_set_global_notrace - set a function to not trace with global tracers
4856 * @buf - the string that holds the function notrace text.
4857 * @len - the length of the string.
4858 * @reset - non zero to reset all filters before applying this filter.
4860 * Notrace Filters denote which functions should not be enabled when tracing
4861 * is enabled. If @buf is NULL and reset is set, all functions will be enabled
4862 * for tracing.
4864 void ftrace_set_global_notrace(unsigned char *buf, int len, int reset)
4866 ftrace_set_regex(&global_ops, buf, len, reset, 0);
4868 EXPORT_SYMBOL_GPL(ftrace_set_global_notrace);
4871 * command line interface to allow users to set filters on boot up.
4873 #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
4874 static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4875 static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
4877 /* Used by function selftest to not test if filter is set */
4878 bool ftrace_filter_param __initdata;
4880 static int __init set_ftrace_notrace(char *str)
4882 ftrace_filter_param = true;
4883 strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
4884 return 1;
4886 __setup("ftrace_notrace=", set_ftrace_notrace);
4888 static int __init set_ftrace_filter(char *str)
4890 ftrace_filter_param = true;
4891 strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
4892 return 1;
4894 __setup("ftrace_filter=", set_ftrace_filter);
4896 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4897 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
4898 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
4899 static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
4901 static int __init set_graph_function(char *str)
4903 strlcpy(ftrace_graph_buf, str, FTRACE_FILTER_SIZE);
4904 return 1;
4906 __setup("ftrace_graph_filter=", set_graph_function);
4908 static int __init set_graph_notrace_function(char *str)
4910 strlcpy(ftrace_graph_notrace_buf, str, FTRACE_FILTER_SIZE);
4911 return 1;
4913 __setup("ftrace_graph_notrace=", set_graph_notrace_function);
4915 static int __init set_graph_max_depth_function(char *str)
4917 if (!str)
4918 return 0;
4919 fgraph_max_depth = simple_strtoul(str, NULL, 0);
4920 return 1;
4922 __setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
4924 static void __init set_ftrace_early_graph(char *buf, int enable)
4926 int ret;
4927 char *func;
4928 struct ftrace_hash *hash;
4930 hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
4931 if (WARN_ON(!hash))
4932 return;
4934 while (buf) {
4935 func = strsep(&buf, ",");
4936 /* we allow only one expression at a time */
4937 ret = ftrace_graph_set_hash(hash, func);
4938 if (ret)
4939 printk(KERN_DEBUG "ftrace: function %s not "
4940 "traceable\n", func);
4943 if (enable)
4944 ftrace_graph_hash = hash;
4945 else
4946 ftrace_graph_notrace_hash = hash;
4948 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4950 void __init
4951 ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable)
4953 char *func;
4955 ftrace_ops_init(ops);
4957 while (buf) {
4958 func = strsep(&buf, ",");
4959 ftrace_set_regex(ops, func, strlen(func), 0, enable);
4963 static void __init set_ftrace_early_filters(void)
4965 if (ftrace_filter_buf[0])
4966 ftrace_set_early_filter(&global_ops, ftrace_filter_buf, 1);
4967 if (ftrace_notrace_buf[0])
4968 ftrace_set_early_filter(&global_ops, ftrace_notrace_buf, 0);
4969 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
4970 if (ftrace_graph_buf[0])
4971 set_ftrace_early_graph(ftrace_graph_buf, 1);
4972 if (ftrace_graph_notrace_buf[0])
4973 set_ftrace_early_graph(ftrace_graph_notrace_buf, 0);
4974 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
4977 int ftrace_regex_release(struct inode *inode, struct file *file)
4979 struct seq_file *m = (struct seq_file *)file->private_data;
4980 struct ftrace_iterator *iter;
4981 struct ftrace_hash **orig_hash;
4982 struct trace_parser *parser;
4983 int filter_hash;
4984 int ret;
4986 if (file->f_mode & FMODE_READ) {
4987 iter = m->private;
4988 seq_release(inode, file);
4989 } else
4990 iter = file->private_data;
4992 parser = &iter->parser;
4993 if (trace_parser_loaded(parser)) {
4994 ftrace_match_records(iter->hash, parser->buffer, parser->idx);
4997 trace_parser_put(parser);
4999 mutex_lock(&iter->ops->func_hash->regex_lock);
5001 if (file->f_mode & FMODE_WRITE) {
5002 filter_hash = !!(iter->flags & FTRACE_ITER_FILTER);
5004 if (filter_hash) {
5005 orig_hash = &iter->ops->func_hash->filter_hash;
5006 if (iter->tr && !list_empty(&iter->tr->mod_trace))
5007 iter->hash->flags |= FTRACE_HASH_FL_MOD;
5008 } else
5009 orig_hash = &iter->ops->func_hash->notrace_hash;
5011 mutex_lock(&ftrace_lock);
5012 ret = ftrace_hash_move_and_update_ops(iter->ops, orig_hash,
5013 iter->hash, filter_hash);
5014 mutex_unlock(&ftrace_lock);
5015 } else {
5016 /* For read only, the hash is the ops hash */
5017 iter->hash = NULL;
5020 mutex_unlock(&iter->ops->func_hash->regex_lock);
5021 free_ftrace_hash(iter->hash);
5022 kfree(iter);
5024 return 0;
5027 static const struct file_operations ftrace_avail_fops = {
5028 .open = ftrace_avail_open,
5029 .read = seq_read,
5030 .llseek = seq_lseek,
5031 .release = seq_release_private,
5034 static const struct file_operations ftrace_enabled_fops = {
5035 .open = ftrace_enabled_open,
5036 .read = seq_read,
5037 .llseek = seq_lseek,
5038 .release = seq_release_private,
5041 static const struct file_operations ftrace_filter_fops = {
5042 .open = ftrace_filter_open,
5043 .read = seq_read,
5044 .write = ftrace_filter_write,
5045 .llseek = tracing_lseek,
5046 .release = ftrace_regex_release,
5049 static const struct file_operations ftrace_notrace_fops = {
5050 .open = ftrace_notrace_open,
5051 .read = seq_read,
5052 .write = ftrace_notrace_write,
5053 .llseek = tracing_lseek,
5054 .release = ftrace_regex_release,
5057 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5059 static DEFINE_MUTEX(graph_lock);
5061 struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
5062 struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
5064 enum graph_filter_type {
5065 GRAPH_FILTER_NOTRACE = 0,
5066 GRAPH_FILTER_FUNCTION,
5069 #define FTRACE_GRAPH_EMPTY ((void *)1)
5071 struct ftrace_graph_data {
5072 struct ftrace_hash *hash;
5073 struct ftrace_func_entry *entry;
5074 int idx; /* for hash table iteration */
5075 enum graph_filter_type type;
5076 struct ftrace_hash *new_hash;
5077 const struct seq_operations *seq_ops;
5078 struct trace_parser parser;
5081 static void *
5082 __g_next(struct seq_file *m, loff_t *pos)
5084 struct ftrace_graph_data *fgd = m->private;
5085 struct ftrace_func_entry *entry = fgd->entry;
5086 struct hlist_head *head;
5087 int i, idx = fgd->idx;
5089 if (*pos >= fgd->hash->count)
5090 return NULL;
5092 if (entry) {
5093 hlist_for_each_entry_continue(entry, hlist) {
5094 fgd->entry = entry;
5095 return entry;
5098 idx++;
5101 for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
5102 head = &fgd->hash->buckets[i];
5103 hlist_for_each_entry(entry, head, hlist) {
5104 fgd->entry = entry;
5105 fgd->idx = i;
5106 return entry;
5109 return NULL;
5112 static void *
5113 g_next(struct seq_file *m, void *v, loff_t *pos)
5115 (*pos)++;
5116 return __g_next(m, pos);
5119 static void *g_start(struct seq_file *m, loff_t *pos)
5121 struct ftrace_graph_data *fgd = m->private;
5123 mutex_lock(&graph_lock);
5125 if (fgd->type == GRAPH_FILTER_FUNCTION)
5126 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5127 lockdep_is_held(&graph_lock));
5128 else
5129 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5130 lockdep_is_held(&graph_lock));
5132 /* Nothing, tell g_show to print all functions are enabled */
5133 if (ftrace_hash_empty(fgd->hash) && !*pos)
5134 return FTRACE_GRAPH_EMPTY;
5136 fgd->idx = 0;
5137 fgd->entry = NULL;
5138 return __g_next(m, pos);
5141 static void g_stop(struct seq_file *m, void *p)
5143 mutex_unlock(&graph_lock);
5146 static int g_show(struct seq_file *m, void *v)
5148 struct ftrace_func_entry *entry = v;
5150 if (!entry)
5151 return 0;
5153 if (entry == FTRACE_GRAPH_EMPTY) {
5154 struct ftrace_graph_data *fgd = m->private;
5156 if (fgd->type == GRAPH_FILTER_FUNCTION)
5157 seq_puts(m, "#### all functions enabled ####\n");
5158 else
5159 seq_puts(m, "#### no functions disabled ####\n");
5160 return 0;
5163 seq_printf(m, "%ps\n", (void *)entry->ip);
5165 return 0;
5168 static const struct seq_operations ftrace_graph_seq_ops = {
5169 .start = g_start,
5170 .next = g_next,
5171 .stop = g_stop,
5172 .show = g_show,
5175 static int
5176 __ftrace_graph_open(struct inode *inode, struct file *file,
5177 struct ftrace_graph_data *fgd)
5179 int ret = 0;
5180 struct ftrace_hash *new_hash = NULL;
5182 if (file->f_mode & FMODE_WRITE) {
5183 const int size_bits = FTRACE_HASH_DEFAULT_BITS;
5185 if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
5186 return -ENOMEM;
5188 if (file->f_flags & O_TRUNC)
5189 new_hash = alloc_ftrace_hash(size_bits);
5190 else
5191 new_hash = alloc_and_copy_ftrace_hash(size_bits,
5192 fgd->hash);
5193 if (!new_hash) {
5194 ret = -ENOMEM;
5195 goto out;
5199 if (file->f_mode & FMODE_READ) {
5200 ret = seq_open(file, &ftrace_graph_seq_ops);
5201 if (!ret) {
5202 struct seq_file *m = file->private_data;
5203 m->private = fgd;
5204 } else {
5205 /* Failed */
5206 free_ftrace_hash(new_hash);
5207 new_hash = NULL;
5209 } else
5210 file->private_data = fgd;
5212 out:
5213 if (ret < 0 && file->f_mode & FMODE_WRITE)
5214 trace_parser_put(&fgd->parser);
5216 fgd->new_hash = new_hash;
5219 * All uses of fgd->hash must be taken with the graph_lock
5220 * held. The graph_lock is going to be released, so force
5221 * fgd->hash to be reinitialized when it is taken again.
5223 fgd->hash = NULL;
5225 return ret;
5228 static int
5229 ftrace_graph_open(struct inode *inode, struct file *file)
5231 struct ftrace_graph_data *fgd;
5232 int ret;
5234 if (unlikely(ftrace_disabled))
5235 return -ENODEV;
5237 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5238 if (fgd == NULL)
5239 return -ENOMEM;
5241 mutex_lock(&graph_lock);
5243 fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
5244 lockdep_is_held(&graph_lock));
5245 fgd->type = GRAPH_FILTER_FUNCTION;
5246 fgd->seq_ops = &ftrace_graph_seq_ops;
5248 ret = __ftrace_graph_open(inode, file, fgd);
5249 if (ret < 0)
5250 kfree(fgd);
5252 mutex_unlock(&graph_lock);
5253 return ret;
5256 static int
5257 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
5259 struct ftrace_graph_data *fgd;
5260 int ret;
5262 if (unlikely(ftrace_disabled))
5263 return -ENODEV;
5265 fgd = kmalloc(sizeof(*fgd), GFP_KERNEL);
5266 if (fgd == NULL)
5267 return -ENOMEM;
5269 mutex_lock(&graph_lock);
5271 fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5272 lockdep_is_held(&graph_lock));
5273 fgd->type = GRAPH_FILTER_NOTRACE;
5274 fgd->seq_ops = &ftrace_graph_seq_ops;
5276 ret = __ftrace_graph_open(inode, file, fgd);
5277 if (ret < 0)
5278 kfree(fgd);
5280 mutex_unlock(&graph_lock);
5281 return ret;
5284 static int
5285 ftrace_graph_release(struct inode *inode, struct file *file)
5287 struct ftrace_graph_data *fgd;
5288 struct ftrace_hash *old_hash, *new_hash;
5289 struct trace_parser *parser;
5290 int ret = 0;
5292 if (file->f_mode & FMODE_READ) {
5293 struct seq_file *m = file->private_data;
5295 fgd = m->private;
5296 seq_release(inode, file);
5297 } else {
5298 fgd = file->private_data;
5302 if (file->f_mode & FMODE_WRITE) {
5304 parser = &fgd->parser;
5306 if (trace_parser_loaded((parser))) {
5307 ret = ftrace_graph_set_hash(fgd->new_hash,
5308 parser->buffer);
5311 trace_parser_put(parser);
5313 new_hash = __ftrace_hash_move(fgd->new_hash);
5314 if (!new_hash) {
5315 ret = -ENOMEM;
5316 goto out;
5319 mutex_lock(&graph_lock);
5321 if (fgd->type == GRAPH_FILTER_FUNCTION) {
5322 old_hash = rcu_dereference_protected(ftrace_graph_hash,
5323 lockdep_is_held(&graph_lock));
5324 rcu_assign_pointer(ftrace_graph_hash, new_hash);
5325 } else {
5326 old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
5327 lockdep_is_held(&graph_lock));
5328 rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
5331 mutex_unlock(&graph_lock);
5333 /* Wait till all users are no longer using the old hash */
5334 synchronize_rcu();
5336 free_ftrace_hash(old_hash);
5339 out:
5340 free_ftrace_hash(fgd->new_hash);
5341 kfree(fgd);
5343 return ret;
5346 static int
5347 ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
5349 struct ftrace_glob func_g;
5350 struct dyn_ftrace *rec;
5351 struct ftrace_page *pg;
5352 struct ftrace_func_entry *entry;
5353 int fail = 1;
5354 int not;
5356 /* decode regex */
5357 func_g.type = filter_parse_regex(buffer, strlen(buffer),
5358 &func_g.search, &not);
5360 func_g.len = strlen(func_g.search);
5362 mutex_lock(&ftrace_lock);
5364 if (unlikely(ftrace_disabled)) {
5365 mutex_unlock(&ftrace_lock);
5366 return -ENODEV;
5369 do_for_each_ftrace_rec(pg, rec) {
5371 if (rec->flags & FTRACE_FL_DISABLED)
5372 continue;
5374 if (ftrace_match_record(rec, &func_g, NULL, 0)) {
5375 entry = ftrace_lookup_ip(hash, rec->ip);
5377 if (!not) {
5378 fail = 0;
5380 if (entry)
5381 continue;
5382 if (add_hash_entry(hash, rec->ip) < 0)
5383 goto out;
5384 } else {
5385 if (entry) {
5386 free_hash_entry(hash, entry);
5387 fail = 0;
5391 } while_for_each_ftrace_rec();
5392 out:
5393 mutex_unlock(&ftrace_lock);
5395 if (fail)
5396 return -EINVAL;
5398 return 0;
5401 static ssize_t
5402 ftrace_graph_write(struct file *file, const char __user *ubuf,
5403 size_t cnt, loff_t *ppos)
5405 ssize_t read, ret = 0;
5406 struct ftrace_graph_data *fgd = file->private_data;
5407 struct trace_parser *parser;
5409 if (!cnt)
5410 return 0;
5412 /* Read mode uses seq functions */
5413 if (file->f_mode & FMODE_READ) {
5414 struct seq_file *m = file->private_data;
5415 fgd = m->private;
5418 parser = &fgd->parser;
5420 read = trace_get_user(parser, ubuf, cnt, ppos);
5422 if (read >= 0 && trace_parser_loaded(parser) &&
5423 !trace_parser_cont(parser)) {
5425 ret = ftrace_graph_set_hash(fgd->new_hash,
5426 parser->buffer);
5427 trace_parser_clear(parser);
5430 if (!ret)
5431 ret = read;
5433 return ret;
5436 static const struct file_operations ftrace_graph_fops = {
5437 .open = ftrace_graph_open,
5438 .read = seq_read,
5439 .write = ftrace_graph_write,
5440 .llseek = tracing_lseek,
5441 .release = ftrace_graph_release,
5444 static const struct file_operations ftrace_graph_notrace_fops = {
5445 .open = ftrace_graph_notrace_open,
5446 .read = seq_read,
5447 .write = ftrace_graph_write,
5448 .llseek = tracing_lseek,
5449 .release = ftrace_graph_release,
5451 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5453 void ftrace_create_filter_files(struct ftrace_ops *ops,
5454 struct dentry *parent)
5457 trace_create_file("set_ftrace_filter", 0644, parent,
5458 ops, &ftrace_filter_fops);
5460 trace_create_file("set_ftrace_notrace", 0644, parent,
5461 ops, &ftrace_notrace_fops);
5465 * The name "destroy_filter_files" is really a misnomer. Although
5466 * in the future, it may actualy delete the files, but this is
5467 * really intended to make sure the ops passed in are disabled
5468 * and that when this function returns, the caller is free to
5469 * free the ops.
5471 * The "destroy" name is only to match the "create" name that this
5472 * should be paired with.
5474 void ftrace_destroy_filter_files(struct ftrace_ops *ops)
5476 mutex_lock(&ftrace_lock);
5477 if (ops->flags & FTRACE_OPS_FL_ENABLED)
5478 ftrace_shutdown(ops, 0);
5479 ops->flags |= FTRACE_OPS_FL_DELETED;
5480 ftrace_free_filter(ops);
5481 mutex_unlock(&ftrace_lock);
5484 static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer)
5487 trace_create_file("available_filter_functions", 0444,
5488 d_tracer, NULL, &ftrace_avail_fops);
5490 trace_create_file("enabled_functions", 0444,
5491 d_tracer, NULL, &ftrace_enabled_fops);
5493 ftrace_create_filter_files(&global_ops, d_tracer);
5495 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
5496 trace_create_file("set_graph_function", 0644, d_tracer,
5497 NULL,
5498 &ftrace_graph_fops);
5499 trace_create_file("set_graph_notrace", 0644, d_tracer,
5500 NULL,
5501 &ftrace_graph_notrace_fops);
5502 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
5504 return 0;
5507 static int ftrace_cmp_ips(const void *a, const void *b)
5509 const unsigned long *ipa = a;
5510 const unsigned long *ipb = b;
5512 if (*ipa > *ipb)
5513 return 1;
5514 if (*ipa < *ipb)
5515 return -1;
5516 return 0;
5519 static int ftrace_process_locs(struct module *mod,
5520 unsigned long *start,
5521 unsigned long *end)
5523 struct ftrace_page *start_pg;
5524 struct ftrace_page *pg;
5525 struct dyn_ftrace *rec;
5526 unsigned long count;
5527 unsigned long *p;
5528 unsigned long addr;
5529 unsigned long flags = 0; /* Shut up gcc */
5530 int ret = -ENOMEM;
5532 count = end - start;
5534 if (!count)
5535 return 0;
5537 sort(start, count, sizeof(*start),
5538 ftrace_cmp_ips, NULL);
5540 start_pg = ftrace_allocate_pages(count);
5541 if (!start_pg)
5542 return -ENOMEM;
5544 mutex_lock(&ftrace_lock);
5547 * Core and each module needs their own pages, as
5548 * modules will free them when they are removed.
5549 * Force a new page to be allocated for modules.
5551 if (!mod) {
5552 WARN_ON(ftrace_pages || ftrace_pages_start);
5553 /* First initialization */
5554 ftrace_pages = ftrace_pages_start = start_pg;
5555 } else {
5556 if (!ftrace_pages)
5557 goto out;
5559 if (WARN_ON(ftrace_pages->next)) {
5560 /* Hmm, we have free pages? */
5561 while (ftrace_pages->next)
5562 ftrace_pages = ftrace_pages->next;
5565 ftrace_pages->next = start_pg;
5568 p = start;
5569 pg = start_pg;
5570 while (p < end) {
5571 addr = ftrace_call_adjust(*p++);
5573 * Some architecture linkers will pad between
5574 * the different mcount_loc sections of different
5575 * object files to satisfy alignments.
5576 * Skip any NULL pointers.
5578 if (!addr)
5579 continue;
5581 if (pg->index == pg->size) {
5582 /* We should have allocated enough */
5583 if (WARN_ON(!pg->next))
5584 break;
5585 pg = pg->next;
5588 rec = &pg->records[pg->index++];
5589 rec->ip = addr;
5592 /* We should have used all pages */
5593 WARN_ON(pg->next);
5595 /* Assign the last page to ftrace_pages */
5596 ftrace_pages = pg;
5599 * We only need to disable interrupts on start up
5600 * because we are modifying code that an interrupt
5601 * may execute, and the modification is not atomic.
5602 * But for modules, nothing runs the code we modify
5603 * until we are finished with it, and there's no
5604 * reason to cause large interrupt latencies while we do it.
5606 if (!mod)
5607 local_irq_save(flags);
5608 ftrace_update_code(mod, start_pg);
5609 if (!mod)
5610 local_irq_restore(flags);
5611 ret = 0;
5612 out:
5613 mutex_unlock(&ftrace_lock);
5615 return ret;
5618 struct ftrace_mod_func {
5619 struct list_head list;
5620 char *name;
5621 unsigned long ip;
5622 unsigned int size;
5625 struct ftrace_mod_map {
5626 struct rcu_head rcu;
5627 struct list_head list;
5628 struct module *mod;
5629 unsigned long start_addr;
5630 unsigned long end_addr;
5631 struct list_head funcs;
5632 unsigned int num_funcs;
5635 #ifdef CONFIG_MODULES
5637 #define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
5639 static LIST_HEAD(ftrace_mod_maps);
5641 static int referenced_filters(struct dyn_ftrace *rec)
5643 struct ftrace_ops *ops;
5644 int cnt = 0;
5646 for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
5647 if (ops_references_rec(ops, rec))
5648 cnt++;
5651 return cnt;
5654 static void
5655 clear_mod_from_hash(struct ftrace_page *pg, struct ftrace_hash *hash)
5657 struct ftrace_func_entry *entry;
5658 struct dyn_ftrace *rec;
5659 int i;
5661 if (ftrace_hash_empty(hash))
5662 return;
5664 for (i = 0; i < pg->index; i++) {
5665 rec = &pg->records[i];
5666 entry = __ftrace_lookup_ip(hash, rec->ip);
5668 * Do not allow this rec to match again.
5669 * Yeah, it may waste some memory, but will be removed
5670 * if/when the hash is modified again.
5672 if (entry)
5673 entry->ip = 0;
5677 /* Clear any records from hashs */
5678 static void clear_mod_from_hashes(struct ftrace_page *pg)
5680 struct trace_array *tr;
5682 mutex_lock(&trace_types_lock);
5683 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
5684 if (!tr->ops || !tr->ops->func_hash)
5685 continue;
5686 mutex_lock(&tr->ops->func_hash->regex_lock);
5687 clear_mod_from_hash(pg, tr->ops->func_hash->filter_hash);
5688 clear_mod_from_hash(pg, tr->ops->func_hash->notrace_hash);
5689 mutex_unlock(&tr->ops->func_hash->regex_lock);
5691 mutex_unlock(&trace_types_lock);
5694 static void ftrace_free_mod_map(struct rcu_head *rcu)
5696 struct ftrace_mod_map *mod_map = container_of(rcu, struct ftrace_mod_map, rcu);
5697 struct ftrace_mod_func *mod_func;
5698 struct ftrace_mod_func *n;
5700 /* All the contents of mod_map are now not visible to readers */
5701 list_for_each_entry_safe(mod_func, n, &mod_map->funcs, list) {
5702 kfree(mod_func->name);
5703 list_del(&mod_func->list);
5704 kfree(mod_func);
5707 kfree(mod_map);
5710 void ftrace_release_mod(struct module *mod)
5712 struct ftrace_mod_map *mod_map;
5713 struct ftrace_mod_map *n;
5714 struct dyn_ftrace *rec;
5715 struct ftrace_page **last_pg;
5716 struct ftrace_page *tmp_page = NULL;
5717 struct ftrace_page *pg;
5718 int order;
5720 mutex_lock(&ftrace_lock);
5722 if (ftrace_disabled)
5723 goto out_unlock;
5725 list_for_each_entry_safe(mod_map, n, &ftrace_mod_maps, list) {
5726 if (mod_map->mod == mod) {
5727 list_del_rcu(&mod_map->list);
5728 call_rcu(&mod_map->rcu, ftrace_free_mod_map);
5729 break;
5734 * Each module has its own ftrace_pages, remove
5735 * them from the list.
5737 last_pg = &ftrace_pages_start;
5738 for (pg = ftrace_pages_start; pg; pg = *last_pg) {
5739 rec = &pg->records[0];
5740 if (within_module_core(rec->ip, mod) ||
5741 within_module_init(rec->ip, mod)) {
5743 * As core pages are first, the first
5744 * page should never be a module page.
5746 if (WARN_ON(pg == ftrace_pages_start))
5747 goto out_unlock;
5749 /* Check if we are deleting the last page */
5750 if (pg == ftrace_pages)
5751 ftrace_pages = next_to_ftrace_page(last_pg);
5753 ftrace_update_tot_cnt -= pg->index;
5754 *last_pg = pg->next;
5756 pg->next = tmp_page;
5757 tmp_page = pg;
5758 } else
5759 last_pg = &pg->next;
5761 out_unlock:
5762 mutex_unlock(&ftrace_lock);
5764 for (pg = tmp_page; pg; pg = tmp_page) {
5766 /* Needs to be called outside of ftrace_lock */
5767 clear_mod_from_hashes(pg);
5769 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
5770 free_pages((unsigned long)pg->records, order);
5771 tmp_page = pg->next;
5772 kfree(pg);
5776 void ftrace_module_enable(struct module *mod)
5778 struct dyn_ftrace *rec;
5779 struct ftrace_page *pg;
5781 mutex_lock(&ftrace_lock);
5783 if (ftrace_disabled)
5784 goto out_unlock;
5787 * If the tracing is enabled, go ahead and enable the record.
5789 * The reason not to enable the record immediatelly is the
5790 * inherent check of ftrace_make_nop/ftrace_make_call for
5791 * correct previous instructions. Making first the NOP
5792 * conversion puts the module to the correct state, thus
5793 * passing the ftrace_make_call check.
5795 * We also delay this to after the module code already set the
5796 * text to read-only, as we now need to set it back to read-write
5797 * so that we can modify the text.
5799 if (ftrace_start_up)
5800 ftrace_arch_code_modify_prepare();
5802 do_for_each_ftrace_rec(pg, rec) {
5803 int cnt;
5805 * do_for_each_ftrace_rec() is a double loop.
5806 * module text shares the pg. If a record is
5807 * not part of this module, then skip this pg,
5808 * which the "break" will do.
5810 if (!within_module_core(rec->ip, mod) &&
5811 !within_module_init(rec->ip, mod))
5812 break;
5814 cnt = 0;
5817 * When adding a module, we need to check if tracers are
5818 * currently enabled and if they are, and can trace this record,
5819 * we need to enable the module functions as well as update the
5820 * reference counts for those function records.
5822 if (ftrace_start_up)
5823 cnt += referenced_filters(rec);
5825 /* This clears FTRACE_FL_DISABLED */
5826 rec->flags = cnt;
5828 if (ftrace_start_up && cnt) {
5829 int failed = __ftrace_replace_code(rec, 1);
5830 if (failed) {
5831 ftrace_bug(failed, rec);
5832 goto out_loop;
5836 } while_for_each_ftrace_rec();
5838 out_loop:
5839 if (ftrace_start_up)
5840 ftrace_arch_code_modify_post_process();
5842 out_unlock:
5843 mutex_unlock(&ftrace_lock);
5845 process_cached_mods(mod->name);
5848 void ftrace_module_init(struct module *mod)
5850 if (ftrace_disabled || !mod->num_ftrace_callsites)
5851 return;
5853 ftrace_process_locs(mod, mod->ftrace_callsites,
5854 mod->ftrace_callsites + mod->num_ftrace_callsites);
5857 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
5858 struct dyn_ftrace *rec)
5860 struct ftrace_mod_func *mod_func;
5861 unsigned long symsize;
5862 unsigned long offset;
5863 char str[KSYM_SYMBOL_LEN];
5864 char *modname;
5865 const char *ret;
5867 ret = kallsyms_lookup(rec->ip, &symsize, &offset, &modname, str);
5868 if (!ret)
5869 return;
5871 mod_func = kmalloc(sizeof(*mod_func), GFP_KERNEL);
5872 if (!mod_func)
5873 return;
5875 mod_func->name = kstrdup(str, GFP_KERNEL);
5876 if (!mod_func->name) {
5877 kfree(mod_func);
5878 return;
5881 mod_func->ip = rec->ip - offset;
5882 mod_func->size = symsize;
5884 mod_map->num_funcs++;
5886 list_add_rcu(&mod_func->list, &mod_map->funcs);
5889 static struct ftrace_mod_map *
5890 allocate_ftrace_mod_map(struct module *mod,
5891 unsigned long start, unsigned long end)
5893 struct ftrace_mod_map *mod_map;
5895 mod_map = kmalloc(sizeof(*mod_map), GFP_KERNEL);
5896 if (!mod_map)
5897 return NULL;
5899 mod_map->mod = mod;
5900 mod_map->start_addr = start;
5901 mod_map->end_addr = end;
5902 mod_map->num_funcs = 0;
5904 INIT_LIST_HEAD_RCU(&mod_map->funcs);
5906 list_add_rcu(&mod_map->list, &ftrace_mod_maps);
5908 return mod_map;
5911 static const char *
5912 ftrace_func_address_lookup(struct ftrace_mod_map *mod_map,
5913 unsigned long addr, unsigned long *size,
5914 unsigned long *off, char *sym)
5916 struct ftrace_mod_func *found_func = NULL;
5917 struct ftrace_mod_func *mod_func;
5919 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5920 if (addr >= mod_func->ip &&
5921 addr < mod_func->ip + mod_func->size) {
5922 found_func = mod_func;
5923 break;
5927 if (found_func) {
5928 if (size)
5929 *size = found_func->size;
5930 if (off)
5931 *off = addr - found_func->ip;
5932 if (sym)
5933 strlcpy(sym, found_func->name, KSYM_NAME_LEN);
5935 return found_func->name;
5938 return NULL;
5941 const char *
5942 ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
5943 unsigned long *off, char **modname, char *sym)
5945 struct ftrace_mod_map *mod_map;
5946 const char *ret = NULL;
5948 /* mod_map is freed via call_rcu() */
5949 preempt_disable();
5950 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5951 ret = ftrace_func_address_lookup(mod_map, addr, size, off, sym);
5952 if (ret) {
5953 if (modname)
5954 *modname = mod_map->mod->name;
5955 break;
5958 preempt_enable();
5960 return ret;
5963 int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
5964 char *type, char *name,
5965 char *module_name, int *exported)
5967 struct ftrace_mod_map *mod_map;
5968 struct ftrace_mod_func *mod_func;
5970 preempt_disable();
5971 list_for_each_entry_rcu(mod_map, &ftrace_mod_maps, list) {
5973 if (symnum >= mod_map->num_funcs) {
5974 symnum -= mod_map->num_funcs;
5975 continue;
5978 list_for_each_entry_rcu(mod_func, &mod_map->funcs, list) {
5979 if (symnum > 1) {
5980 symnum--;
5981 continue;
5984 *value = mod_func->ip;
5985 *type = 'T';
5986 strlcpy(name, mod_func->name, KSYM_NAME_LEN);
5987 strlcpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
5988 *exported = 1;
5989 preempt_enable();
5990 return 0;
5992 WARN_ON(1);
5993 break;
5995 preempt_enable();
5996 return -ERANGE;
5999 #else
6000 static void save_ftrace_mod_rec(struct ftrace_mod_map *mod_map,
6001 struct dyn_ftrace *rec) { }
6002 static inline struct ftrace_mod_map *
6003 allocate_ftrace_mod_map(struct module *mod,
6004 unsigned long start, unsigned long end)
6006 return NULL;
6008 #endif /* CONFIG_MODULES */
6010 struct ftrace_init_func {
6011 struct list_head list;
6012 unsigned long ip;
6015 /* Clear any init ips from hashes */
6016 static void
6017 clear_func_from_hash(struct ftrace_init_func *func, struct ftrace_hash *hash)
6019 struct ftrace_func_entry *entry;
6021 if (ftrace_hash_empty(hash))
6022 return;
6024 entry = __ftrace_lookup_ip(hash, func->ip);
6027 * Do not allow this rec to match again.
6028 * Yeah, it may waste some memory, but will be removed
6029 * if/when the hash is modified again.
6031 if (entry)
6032 entry->ip = 0;
6035 static void
6036 clear_func_from_hashes(struct ftrace_init_func *func)
6038 struct trace_array *tr;
6040 mutex_lock(&trace_types_lock);
6041 list_for_each_entry(tr, &ftrace_trace_arrays, list) {
6042 if (!tr->ops || !tr->ops->func_hash)
6043 continue;
6044 mutex_lock(&tr->ops->func_hash->regex_lock);
6045 clear_func_from_hash(func, tr->ops->func_hash->filter_hash);
6046 clear_func_from_hash(func, tr->ops->func_hash->notrace_hash);
6047 mutex_unlock(&tr->ops->func_hash->regex_lock);
6049 mutex_unlock(&trace_types_lock);
6052 static void add_to_clear_hash_list(struct list_head *clear_list,
6053 struct dyn_ftrace *rec)
6055 struct ftrace_init_func *func;
6057 func = kmalloc(sizeof(*func), GFP_KERNEL);
6058 if (!func) {
6059 WARN_ONCE(1, "alloc failure, ftrace filter could be stale\n");
6060 return;
6063 func->ip = rec->ip;
6064 list_add(&func->list, clear_list);
6067 void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
6069 unsigned long start = (unsigned long)(start_ptr);
6070 unsigned long end = (unsigned long)(end_ptr);
6071 struct ftrace_page **last_pg = &ftrace_pages_start;
6072 struct ftrace_page *pg;
6073 struct dyn_ftrace *rec;
6074 struct dyn_ftrace key;
6075 struct ftrace_mod_map *mod_map = NULL;
6076 struct ftrace_init_func *func, *func_next;
6077 struct list_head clear_hash;
6078 int order;
6080 INIT_LIST_HEAD(&clear_hash);
6082 key.ip = start;
6083 key.flags = end; /* overload flags, as it is unsigned long */
6085 mutex_lock(&ftrace_lock);
6088 * If we are freeing module init memory, then check if
6089 * any tracer is active. If so, we need to save a mapping of
6090 * the module functions being freed with the address.
6092 if (mod && ftrace_ops_list != &ftrace_list_end)
6093 mod_map = allocate_ftrace_mod_map(mod, start, end);
6095 for (pg = ftrace_pages_start; pg; last_pg = &pg->next, pg = *last_pg) {
6096 if (end < pg->records[0].ip ||
6097 start >= (pg->records[pg->index - 1].ip + MCOUNT_INSN_SIZE))
6098 continue;
6099 again:
6100 rec = bsearch(&key, pg->records, pg->index,
6101 sizeof(struct dyn_ftrace),
6102 ftrace_cmp_recs);
6103 if (!rec)
6104 continue;
6106 /* rec will be cleared from hashes after ftrace_lock unlock */
6107 add_to_clear_hash_list(&clear_hash, rec);
6109 if (mod_map)
6110 save_ftrace_mod_rec(mod_map, rec);
6112 pg->index--;
6113 ftrace_update_tot_cnt--;
6114 if (!pg->index) {
6115 *last_pg = pg->next;
6116 order = get_count_order(pg->size / ENTRIES_PER_PAGE);
6117 free_pages((unsigned long)pg->records, order);
6118 kfree(pg);
6119 pg = container_of(last_pg, struct ftrace_page, next);
6120 if (!(*last_pg))
6121 ftrace_pages = pg;
6122 continue;
6124 memmove(rec, rec + 1,
6125 (pg->index - (rec - pg->records)) * sizeof(*rec));
6126 /* More than one function may be in this block */
6127 goto again;
6129 mutex_unlock(&ftrace_lock);
6131 list_for_each_entry_safe(func, func_next, &clear_hash, list) {
6132 clear_func_from_hashes(func);
6133 kfree(func);
6137 void __init ftrace_free_init_mem(void)
6139 void *start = (void *)(&__init_begin);
6140 void *end = (void *)(&__init_end);
6142 ftrace_free_mem(NULL, start, end);
6145 void __init ftrace_init(void)
6147 extern unsigned long __start_mcount_loc[];
6148 extern unsigned long __stop_mcount_loc[];
6149 unsigned long count, flags;
6150 int ret;
6152 local_irq_save(flags);
6153 ret = ftrace_dyn_arch_init();
6154 local_irq_restore(flags);
6155 if (ret)
6156 goto failed;
6158 count = __stop_mcount_loc - __start_mcount_loc;
6159 if (!count) {
6160 pr_info("ftrace: No functions to be traced?\n");
6161 goto failed;
6164 pr_info("ftrace: allocating %ld entries in %ld pages\n",
6165 count, count / ENTRIES_PER_PAGE + 1);
6167 last_ftrace_enabled = ftrace_enabled = 1;
6169 ret = ftrace_process_locs(NULL,
6170 __start_mcount_loc,
6171 __stop_mcount_loc);
6173 set_ftrace_early_filters();
6175 return;
6176 failed:
6177 ftrace_disabled = 1;
6180 /* Do nothing if arch does not support this */
6181 void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops)
6185 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6187 arch_ftrace_update_trampoline(ops);
6190 void ftrace_init_trace_array(struct trace_array *tr)
6192 INIT_LIST_HEAD(&tr->func_probes);
6193 INIT_LIST_HEAD(&tr->mod_trace);
6194 INIT_LIST_HEAD(&tr->mod_notrace);
6196 #else
6198 struct ftrace_ops global_ops = {
6199 .func = ftrace_stub,
6200 .flags = FTRACE_OPS_FL_RECURSION_SAFE |
6201 FTRACE_OPS_FL_INITIALIZED |
6202 FTRACE_OPS_FL_PID,
6205 static int __init ftrace_nodyn_init(void)
6207 ftrace_enabled = 1;
6208 return 0;
6210 core_initcall(ftrace_nodyn_init);
6212 static inline int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { return 0; }
6213 static inline void ftrace_startup_enable(int command) { }
6214 static inline void ftrace_startup_all(int command) { }
6216 # define ftrace_startup_sysctl() do { } while (0)
6217 # define ftrace_shutdown_sysctl() do { } while (0)
6219 static void ftrace_update_trampoline(struct ftrace_ops *ops)
6223 #endif /* CONFIG_DYNAMIC_FTRACE */
6225 __init void ftrace_init_global_array_ops(struct trace_array *tr)
6227 tr->ops = &global_ops;
6228 tr->ops->private = tr;
6229 ftrace_init_trace_array(tr);
6232 void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func)
6234 /* If we filter on pids, update to use the pid function */
6235 if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
6236 if (WARN_ON(tr->ops->func != ftrace_stub))
6237 printk("ftrace ops had %pS for function\n",
6238 tr->ops->func);
6240 tr->ops->func = func;
6241 tr->ops->private = tr;
6244 void ftrace_reset_array_ops(struct trace_array *tr)
6246 tr->ops->func = ftrace_stub;
6249 static inline void
6250 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6251 struct ftrace_ops *ignored, struct pt_regs *regs)
6253 struct ftrace_ops *op;
6254 int bit;
6256 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6257 if (bit < 0)
6258 return;
6261 * Some of the ops may be dynamically allocated,
6262 * they must be freed after a synchronize_rcu().
6264 preempt_disable_notrace();
6266 do_for_each_ftrace_op(op, ftrace_ops_list) {
6268 * Check the following for each ops before calling their func:
6269 * if RCU flag is set, then rcu_is_watching() must be true
6270 * if PER_CPU is set, then ftrace_function_local_disable()
6271 * must be false
6272 * Otherwise test if the ip matches the ops filter
6274 * If any of the above fails then the op->func() is not executed.
6276 if ((!(op->flags & FTRACE_OPS_FL_RCU) || rcu_is_watching()) &&
6277 ftrace_ops_test(op, ip, regs)) {
6278 if (FTRACE_WARN_ON(!op->func)) {
6279 pr_warn("op=%p %pS\n", op, op);
6280 goto out;
6282 op->func(ip, parent_ip, op, regs);
6284 } while_for_each_ftrace_op(op);
6285 out:
6286 preempt_enable_notrace();
6287 trace_clear_recursion(bit);
6291 * Some archs only support passing ip and parent_ip. Even though
6292 * the list function ignores the op parameter, we do not want any
6293 * C side effects, where a function is called without the caller
6294 * sending a third parameter.
6295 * Archs are to support both the regs and ftrace_ops at the same time.
6296 * If they support ftrace_ops, it is assumed they support regs.
6297 * If call backs want to use regs, they must either check for regs
6298 * being NULL, or CONFIG_DYNAMIC_FTRACE_WITH_REGS.
6299 * Note, CONFIG_DYNAMIC_FTRACE_WITH_REGS expects a full regs to be saved.
6300 * An architecture can pass partial regs with ftrace_ops and still
6301 * set the ARCH_SUPPORTS_FTRACE_OPS.
6303 #if ARCH_SUPPORTS_FTRACE_OPS
6304 static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
6305 struct ftrace_ops *op, struct pt_regs *regs)
6307 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
6309 #else
6310 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
6312 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
6314 #endif
6317 * If there's only one function registered but it does not support
6318 * recursion, needs RCU protection and/or requires per cpu handling, then
6319 * this function will be called by the mcount trampoline.
6321 static void ftrace_ops_assist_func(unsigned long ip, unsigned long parent_ip,
6322 struct ftrace_ops *op, struct pt_regs *regs)
6324 int bit;
6326 if ((op->flags & FTRACE_OPS_FL_RCU) && !rcu_is_watching())
6327 return;
6329 bit = trace_test_and_set_recursion(TRACE_LIST_START, TRACE_LIST_MAX);
6330 if (bit < 0)
6331 return;
6333 preempt_disable_notrace();
6335 op->func(ip, parent_ip, op, regs);
6337 preempt_enable_notrace();
6338 trace_clear_recursion(bit);
6342 * ftrace_ops_get_func - get the function a trampoline should call
6343 * @ops: the ops to get the function for
6345 * Normally the mcount trampoline will call the ops->func, but there
6346 * are times that it should not. For example, if the ops does not
6347 * have its own recursion protection, then it should call the
6348 * ftrace_ops_assist_func() instead.
6350 * Returns the function that the trampoline should call for @ops.
6352 ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
6355 * If the function does not handle recursion, needs to be RCU safe,
6356 * or does per cpu logic, then we need to call the assist handler.
6358 if (!(ops->flags & FTRACE_OPS_FL_RECURSION_SAFE) ||
6359 ops->flags & FTRACE_OPS_FL_RCU)
6360 return ftrace_ops_assist_func;
6362 return ops->func;
6365 static void
6366 ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
6367 struct task_struct *prev, struct task_struct *next)
6369 struct trace_array *tr = data;
6370 struct trace_pid_list *pid_list;
6372 pid_list = rcu_dereference_sched(tr->function_pids);
6374 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6375 trace_ignore_this_task(pid_list, next));
6378 static void
6379 ftrace_pid_follow_sched_process_fork(void *data,
6380 struct task_struct *self,
6381 struct task_struct *task)
6383 struct trace_pid_list *pid_list;
6384 struct trace_array *tr = data;
6386 pid_list = rcu_dereference_sched(tr->function_pids);
6387 trace_filter_add_remove_task(pid_list, self, task);
6390 static void
6391 ftrace_pid_follow_sched_process_exit(void *data, struct task_struct *task)
6393 struct trace_pid_list *pid_list;
6394 struct trace_array *tr = data;
6396 pid_list = rcu_dereference_sched(tr->function_pids);
6397 trace_filter_add_remove_task(pid_list, NULL, task);
6400 void ftrace_pid_follow_fork(struct trace_array *tr, bool enable)
6402 if (enable) {
6403 register_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6404 tr);
6405 register_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6406 tr);
6407 } else {
6408 unregister_trace_sched_process_fork(ftrace_pid_follow_sched_process_fork,
6409 tr);
6410 unregister_trace_sched_process_exit(ftrace_pid_follow_sched_process_exit,
6411 tr);
6415 static void clear_ftrace_pids(struct trace_array *tr)
6417 struct trace_pid_list *pid_list;
6418 int cpu;
6420 pid_list = rcu_dereference_protected(tr->function_pids,
6421 lockdep_is_held(&ftrace_lock));
6422 if (!pid_list)
6423 return;
6425 unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6427 for_each_possible_cpu(cpu)
6428 per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
6430 rcu_assign_pointer(tr->function_pids, NULL);
6432 /* Wait till all users are no longer using pid filtering */
6433 synchronize_rcu();
6435 trace_free_pid_list(pid_list);
6438 void ftrace_clear_pids(struct trace_array *tr)
6440 mutex_lock(&ftrace_lock);
6442 clear_ftrace_pids(tr);
6444 mutex_unlock(&ftrace_lock);
6447 static void ftrace_pid_reset(struct trace_array *tr)
6449 mutex_lock(&ftrace_lock);
6450 clear_ftrace_pids(tr);
6452 ftrace_update_pid_func();
6453 ftrace_startup_all(0);
6455 mutex_unlock(&ftrace_lock);
6458 /* Greater than any max PID */
6459 #define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
6461 static void *fpid_start(struct seq_file *m, loff_t *pos)
6462 __acquires(RCU)
6464 struct trace_pid_list *pid_list;
6465 struct trace_array *tr = m->private;
6467 mutex_lock(&ftrace_lock);
6468 rcu_read_lock_sched();
6470 pid_list = rcu_dereference_sched(tr->function_pids);
6472 if (!pid_list)
6473 return !(*pos) ? FTRACE_NO_PIDS : NULL;
6475 return trace_pid_start(pid_list, pos);
6478 static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
6480 struct trace_array *tr = m->private;
6481 struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
6483 if (v == FTRACE_NO_PIDS)
6484 return NULL;
6486 return trace_pid_next(pid_list, v, pos);
6489 static void fpid_stop(struct seq_file *m, void *p)
6490 __releases(RCU)
6492 rcu_read_unlock_sched();
6493 mutex_unlock(&ftrace_lock);
6496 static int fpid_show(struct seq_file *m, void *v)
6498 if (v == FTRACE_NO_PIDS) {
6499 seq_puts(m, "no pid\n");
6500 return 0;
6503 return trace_pid_show(m, v);
6506 static const struct seq_operations ftrace_pid_sops = {
6507 .start = fpid_start,
6508 .next = fpid_next,
6509 .stop = fpid_stop,
6510 .show = fpid_show,
6513 static int
6514 ftrace_pid_open(struct inode *inode, struct file *file)
6516 struct trace_array *tr = inode->i_private;
6517 struct seq_file *m;
6518 int ret = 0;
6520 if (trace_array_get(tr) < 0)
6521 return -ENODEV;
6523 if ((file->f_mode & FMODE_WRITE) &&
6524 (file->f_flags & O_TRUNC))
6525 ftrace_pid_reset(tr);
6527 ret = seq_open(file, &ftrace_pid_sops);
6528 if (ret < 0) {
6529 trace_array_put(tr);
6530 } else {
6531 m = file->private_data;
6532 /* copy tr over to seq ops */
6533 m->private = tr;
6536 return ret;
6539 static void ignore_task_cpu(void *data)
6541 struct trace_array *tr = data;
6542 struct trace_pid_list *pid_list;
6545 * This function is called by on_each_cpu() while the
6546 * event_mutex is held.
6548 pid_list = rcu_dereference_protected(tr->function_pids,
6549 mutex_is_locked(&ftrace_lock));
6551 this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
6552 trace_ignore_this_task(pid_list, current));
6555 static ssize_t
6556 ftrace_pid_write(struct file *filp, const char __user *ubuf,
6557 size_t cnt, loff_t *ppos)
6559 struct seq_file *m = filp->private_data;
6560 struct trace_array *tr = m->private;
6561 struct trace_pid_list *filtered_pids = NULL;
6562 struct trace_pid_list *pid_list;
6563 ssize_t ret;
6565 if (!cnt)
6566 return 0;
6568 mutex_lock(&ftrace_lock);
6570 filtered_pids = rcu_dereference_protected(tr->function_pids,
6571 lockdep_is_held(&ftrace_lock));
6573 ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
6574 if (ret < 0)
6575 goto out;
6577 rcu_assign_pointer(tr->function_pids, pid_list);
6579 if (filtered_pids) {
6580 synchronize_rcu();
6581 trace_free_pid_list(filtered_pids);
6582 } else if (pid_list) {
6583 /* Register a probe to set whether to ignore the tracing of a task */
6584 register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
6588 * Ignoring of pids is done at task switch. But we have to
6589 * check for those tasks that are currently running.
6590 * Always do this in case a pid was appended or removed.
6592 on_each_cpu(ignore_task_cpu, tr, 1);
6594 ftrace_update_pid_func();
6595 ftrace_startup_all(0);
6596 out:
6597 mutex_unlock(&ftrace_lock);
6599 if (ret > 0)
6600 *ppos += ret;
6602 return ret;
6605 static int
6606 ftrace_pid_release(struct inode *inode, struct file *file)
6608 struct trace_array *tr = inode->i_private;
6610 trace_array_put(tr);
6612 return seq_release(inode, file);
6615 static const struct file_operations ftrace_pid_fops = {
6616 .open = ftrace_pid_open,
6617 .write = ftrace_pid_write,
6618 .read = seq_read,
6619 .llseek = tracing_lseek,
6620 .release = ftrace_pid_release,
6623 void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
6625 trace_create_file("set_ftrace_pid", 0644, d_tracer,
6626 tr, &ftrace_pid_fops);
6629 void __init ftrace_init_tracefs_toplevel(struct trace_array *tr,
6630 struct dentry *d_tracer)
6632 /* Only the top level directory has the dyn_tracefs and profile */
6633 WARN_ON(!(tr->flags & TRACE_ARRAY_FL_GLOBAL));
6635 ftrace_init_dyn_tracefs(d_tracer);
6636 ftrace_profile_tracefs(d_tracer);
6640 * ftrace_kill - kill ftrace
6642 * This function should be used by panic code. It stops ftrace
6643 * but in a not so nice way. If you need to simply kill ftrace
6644 * from a non-atomic section, use ftrace_kill.
6646 void ftrace_kill(void)
6648 ftrace_disabled = 1;
6649 ftrace_enabled = 0;
6650 ftrace_trace_function = ftrace_stub;
6654 * Test if ftrace is dead or not.
6656 int ftrace_is_dead(void)
6658 return ftrace_disabled;
6662 * register_ftrace_function - register a function for profiling
6663 * @ops - ops structure that holds the function for profiling.
6665 * Register a function to be called by all functions in the
6666 * kernel.
6668 * Note: @ops->func and all the functions it calls must be labeled
6669 * with "notrace", otherwise it will go into a
6670 * recursive loop.
6672 int register_ftrace_function(struct ftrace_ops *ops)
6674 int ret = -1;
6676 ftrace_ops_init(ops);
6678 mutex_lock(&ftrace_lock);
6680 ret = ftrace_startup(ops, 0);
6682 mutex_unlock(&ftrace_lock);
6684 return ret;
6686 EXPORT_SYMBOL_GPL(register_ftrace_function);
6689 * unregister_ftrace_function - unregister a function for profiling.
6690 * @ops - ops structure that holds the function to unregister
6692 * Unregister a function that was added to be called by ftrace profiling.
6694 int unregister_ftrace_function(struct ftrace_ops *ops)
6696 int ret;
6698 mutex_lock(&ftrace_lock);
6699 ret = ftrace_shutdown(ops, 0);
6700 mutex_unlock(&ftrace_lock);
6702 return ret;
6704 EXPORT_SYMBOL_GPL(unregister_ftrace_function);
6707 ftrace_enable_sysctl(struct ctl_table *table, int write,
6708 void __user *buffer, size_t *lenp,
6709 loff_t *ppos)
6711 int ret = -ENODEV;
6713 mutex_lock(&ftrace_lock);
6715 if (unlikely(ftrace_disabled))
6716 goto out;
6718 ret = proc_dointvec(table, write, buffer, lenp, ppos);
6720 if (ret || !write || (last_ftrace_enabled == !!ftrace_enabled))
6721 goto out;
6723 last_ftrace_enabled = !!ftrace_enabled;
6725 if (ftrace_enabled) {
6727 /* we are starting ftrace again */
6728 if (rcu_dereference_protected(ftrace_ops_list,
6729 lockdep_is_held(&ftrace_lock)) != &ftrace_list_end)
6730 update_ftrace_function();
6732 ftrace_startup_sysctl();
6734 } else {
6735 /* stopping ftrace calls (just send to ftrace_stub) */
6736 ftrace_trace_function = ftrace_stub;
6738 ftrace_shutdown_sysctl();
6741 out:
6742 mutex_unlock(&ftrace_lock);
6743 return ret;